59 results on '"V. Sednev"'
Search Results
2. Experience of minimally invasive treatment for early rectal cancer
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S. V. Vasil’ev, E. S. Savicheva, A. V. Semenov, D. E. Popov, A. N. Klimenko, A. V. Sednev, and E. V. Smirnova
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early rectal cancer ,local excision ,transanal endoscopic microsurgery ,endorectal ultrasound ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Objective. The aim of this study is to evaluate the experience with minimally invasive transanal operations and to improve treatment results in patients with early rectal cancer; to assess the accuracy of endorectal ultrasound (ERUS) in preoperative staging of rectal cancer. Materials and methods. The present clinical trial includes 38 selected patients who were underwent minimally invasive transanal procedures for early rectal cancers. 22 (58 %) patients were operated by transanal endoscopic microsurgery, 16 (42 %) were underwent transanal local excision. The study population consisted of 20 men and 18 women; average age was 64 (range 42–84) years. The main outcome measures included the operation time, the intra- and postoperative complication rate, negative microscopic margin rate, specimen fragmentation rate, oncological results (local recurrence and distant metastasis rate). Comparison of ERUS preoperative staging and pathological staging was performed to identify the accuracy of ERUS. The postoperative surveillance protocol was applied to all patients. Results. The median operative time was 56 (30–110) minutes. Postoperative complications occurred in 2 patients (5.2 %). There was no mortality. All pathological specimens were removed en block without fragmentation. Final histology revealed pTis – 10 (26 %), pT1sm1 – 9 (24 %), pT1sm2 – 12 (32 %), pT1sm3 – 5 (13 %) and pT2 – 2 (5 %) adenocarcinomas with negative resection margins (R0). The overall accuracy of ERUS for preoperative T stage was 78.9 %; for Tis was 80.0 % and for T1 – 85.0 %. All 7 patients in the pT1sm3 and pT2 groups were offered immediate radical surgery or adjuvant chemoradiotherapy. The follow-up period was from 5 to 60 (median 36) months. There was one local recurrence (2.6 %) in 6 months after local excision in a patient with pT1sm3. This patient underwent total mesorectumectomy. Conclusions. Selected patients with “low-risk” early rectal cancer and favorable features may be effectively treated with minimally invasive transanal operations without jeopardizing long-term oncological results. The lack of lymphadenectomy represents the main concern of this approach for the treatment of rectal cancer. Further follow-up is necessary. Preoperative ERUS has a good accuracy with pathologic T stage and can guide transanal procedure in early rectal cancer.
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- 2017
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3. PERINATAL TRIGLYCERIDE AND CHOLESTEROL METABOLIC DISTURBANCES IN NEWBORN INFANTS
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S. A. Perepelitsa and O. V. Sednev
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perinatal hypoxia ,lipid metabolism ,triglycerides ,cholesterol ,newborn infants ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Objective. Investigate the impact of the course of pregnancy and labor on some lipid metabolic disturbances in newborn infants.Subjects and methods. The anamnestic data of the course of pregnancy, which were used to identify a high risk for intranatal hypoxia and the birth of a critically ill baby, were analyzed in 217 pregnant women. In addition to assessment of a baby's status at birth, the newborn infants underwent measurements of cholesterol and triglyc-erides in their central venous blood just after birth and on day 5 of life Results. The low levels of triglycerides and cholesterol are an inherent feature in the newborns born via an emergency cesarean section due to bleeding-complicated placental presentation or abruption and other obstetric causes. The most critical plasma level of triglycerides in extremely premature infants born at 22—29 weeks' gestation and in those having extremely low birth weight was no more than 0.01—0.2 mmol/l. Gestational age and birth weight have an impact on the production of triglycerides. Acute intranatal hypoxia affects the perinatal concen-tration of cholesterol in the newborns; the severer is hypoxia, the lower are blood cholesterol levels.Conclusion. Varying perinatal triglyceride and cholesterol metabolic disturbances are specific in newborn infants with respiratory failure who were born via an emergency cesarean section due to placental abruption or discoordinated labor activity. The low blood levels of the test substances are detectable in babies at birth. Gestational age and birth weight are another factors that influence blood triglyceride concentrations. The lowest triglyceride levels are a characteristic feature in newborn infants at 22—29 weeks' gestation and in those having extremely low birth weight.
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- 2016
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4. Pathogenetic Role of Cholesterol and Triglyceride Metabolic Disturbances in the Development of Critical Conditions
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S. A. Perepelitsa and O. V. Sednev
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lipids ,cholesterol ,triglycerides ,surfactant ,respiratory failure ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
The review considers mechanisms for the development of respiratory failure caused by lipid metabolic disturbances. It gives data on the lung surfactant composition and lipid imbalance in severe concomitant injury, sepsis, and gestosis. Information on the prenatal and postnatal synthesis of triglycerides and cholesterol is detailed.
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- 2015
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5. Physical Modeling of Dislocation Connection in LEDs under Different External Impacts
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A. V. Gradoboev, A. V. Simonova, K. N. Orlova, and V. V. Sednev
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Materials science ,Ohmic Resistance ,law ,Dislocation ,Instrumentation ,Engineering physics ,Light-emitting diode ,law.invention ,Connection (mathematics) - Abstract
A method for physical modeling of the influence of bulk leakage-current channels (dislocations) on the electrophysical and lighting characteristics of LEDs by connecting the p–n junction of an LED in parallel to an ohmic resistance or another p–n junction is described. The relationships that allow one to determine the change in the electrophysical and lighting characteristics of LEDs under the influence of various external factors (ionizing radiation, long-term operation, etc.) have been established. Using the obtained relationships, it is possible to determine the electrophysical characteristics of dislocations according to the changes in the electrophysical and lighting characteristics of LEDs, taking the role of dislocations into account. Based on the literature data, the efficiency of using the established relationships in the analysis of the characteristics of LEDs that are exposed to external impacts has been shown.
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- 2021
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6. A Technique for Studying the Resistance of LEDS to Irradiation by Fast Neutrons at the IRT-T Reactor
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E. G. Yemets, V. V. Sednev, A. V. Gradoboev, V. A. Varlachev, and E. A. Bondarenko
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chemistry.chemical_compound ,Materials science ,chemistry ,law ,Nuclear engineering ,Degradation (geology) ,Irradiation ,Boron carbide ,Instrumentation ,Fluence ,Neutron temperature ,Light-emitting diode ,law.invention - Abstract
—A technique for studying the resistance of IR-wavelength LEDs to the action of fast neutrons at the IRT-T reactor is described. A thermal neutron filter based on boron carbide and cadmium has been developed for the GEC-6 horizontal experimental channel of the IRT-T reactor. The identity of degradation processes in LEDs is shown when exposed to fast neutrons with pulsed (BARS-4 reactor) and continuous (GEC-6 of IRT-T reactor) fluence. The developed technique can be recommended for studying the resistance of various materials and electronic products to the action of fast neutrons in various irradiation regimes.
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- 2021
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7. Investigation of the Depth and Rate of Ion Etching of QWIP Structures
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M. V. Sednev, N. S. Trukhacheva, A. V. Trukhachev, A. I. Dirochka, and K. O. Boltar
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Radiation ,Materials science ,business.industry ,Etching rate ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Ion ,Etching (microfabrication) ,Optoelectronics ,Contact layer ,Electrical and Electronic Engineering ,business ,Quantum well ,Molecular beam epitaxy - Abstract
In this study we investigated the dependences of the rate of ion-beam etching of the upper contact layer (GaAs:Si), an active region consisting of a 50-fold alternation of barrier layers (AlxGa1–xAs) and quantum wells (GaAs:Si) and the lower contact layer (GaAs:Si) along the depth of QWIP structures based on GaAs–AlGaAs, fabricated by molecular beam epitaxy (MBE), in order to determine the effect of the composition of various layers on the etching rate and the ability to complete the etching process to the desired depth in time.
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- 2021
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8. MODELS FOR EVALUATING THE EFFECTIVENESS OF ENGINEERING SUPPORT OF RESCUE UNITS ACTIONS
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A. Smurov and V. Sednev
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Engineering management ,Computer science ,Engineering support - Published
- 2021
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9. EVALUATING WORK ORGANIZATION ON EQUIPPING FIELD WATER SUPPLY POINT
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V. Sednev
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Work organization ,Field (physics) ,business.industry ,Computer science ,Water supply ,Point (geometry) ,business ,Civil engineering - Abstract
Purpose. The increase in number and scales of emergencies consequences, the complexity of the tasks for the solution of which rescue units must be ready requires predicting the results of planned actions and applying mathematical modeling methods to substantiate decisions. The use of mathematical models should help reveal the patterns of rescue units actions on improving the principles of their application, methods of fulfilling their support tasks. Analytical models make it possible to establish formula dependence between the conditions of the situation, the elements of the decision to be made and the effectiveness of the task performance according to the selected criterion. Statistical methods make it possible to more fully take into account the probabilistic nature of the simulated processes and they are most effective in cases when the analytical description of the simulated process presents great difficulties, or it is practically impossible due to significant uncertainty of the initial information. The best results can be obtained with the combined use of analytical and statistical models: the analytical model allows approximately figuring out the basic laws of the phenomenon, outlining its contours, and any further clarification can be obtained by statistical modeling. Therefore, the article discusses the use of the statistical test method for organizing implementation of first priority engineering tasks performed by rescue units. Methods. To obtain the results general scientific and special methods of scientific knowledge including analysis, synthesis, generalization were used; they were based on the provisions of systems theory, operations research, information theory and the method of statistical tests. Findings. A scientific and methodological approach is developed to improve the effectiveness of emergency rescue units use in the emergency area on the example of their equipping a field water supply point. Research application field. The results are applicable to substantiate a set of means for performing tasks and operations by rescue teams. Conclusions. The developed scientific and methodological approach makes it possible to assess the effectiveness of organizing the tasks performance in the emergency area by emergency rescue teams in general, and, in particular, equipping the field water supply point, and it also serves as a basis for improving the work of management bodies at all levels.
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- 2021
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10. Estimation of the Penetration Depth of an Impactor with a Hemispherical Head Part into a Semi-Infinite Medium when Penetrated along the Normal to the Surface
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A. V. Sednev, V. A. Sednev, and S. L. Kopnyshev
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Surface (mathematics) ,Acceleration ,Materials science ,Semi-infinite ,Back pressure ,Mechanical Engineering ,Head (vessel) ,Temporal change ,Penetration (firestop) ,Mechanics ,Safety, Risk, Reliability and Quality ,Penetration depth ,Industrial and Manufacturing Engineering - Abstract
The problem of the penetration of a solid nondeformable impactor with a hemispherical head part into a semi-infinite medium at the elastoplastic stage of interaction with known characteristics of the impactor, the physical and mechanical characteristics of the medium, and the initial conditions of penetration. The process of the impactor movement is identified with the process of the formation of a spherical cavity in the medium, which allows one to use the camouflage equation for determining the back pressure of the medium. The relations obtained make it possible to trace the temporal change of the penetration depth, speed, and acceleration of the impactor.
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- 2020
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11. ASSESSING THE CONSEQUENCES OF METEOROIDS IMPACT ON THE RUSSIAN FEDERATION SUBJECTS AREA
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V. Sednev and D. Blinov
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Economy ,Meteoroid ,Political science ,Russian federation - Published
- 2020
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12. High-Throughput Activity Profiling of RNA-Cleaving DNA Catalysts by Deoxyribozyme Sequencing (DZ-seq)
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Maksim V. Sednev, Anam Liaqat, and Claudia Höbartner
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RNA Cleavage ,Colloid and Surface Chemistry ,High-Throughput Nucleotide Sequencing ,Nucleic Acid Conformation ,RNA ,General Chemistry ,DNA, Catalytic ,Biochemistry ,Catalysis ,ddc:547 ,Substrate Specificity - Abstract
RNA-cleaving deoxyribozymes have found broad application as useful tools for RNA biochemistry. However, tedious in vitro selection procedures combined with laborious characterization of individual candidate catalysts hinder the discovery of novel catalytic motifs. Here, we present a new high-throughput sequencing method, DZ-seq, which directly measures activity and localizes cleavage sites of thousands of deoxyribozymes. DZ-seq exploits A-tailing followed by reverse transcription with an oligo-dT primer to capture the cleavage status and sequences of both deoxyribozyme and RNA substrate. We validated DZ-seq by conventional analytical methods and demonstrated its utility by discovery of novel deoxyribozymes that allow for cleaving challenging RNA targets or the analysis of RNA modification states.
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- 2022
13. In Vitro Selection of Deoxyribozymes for the Detection of RNA Modifications
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Anam, Liaqat, Maksim V, Sednev, and Claudia, Höbartner
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RNA ,DNA ,DNA, Catalytic ,Methylation ,Gene Library ,Research Article ,ddc:547 - Abstract
Deoxyribozymes are artificially evolved DNA molecules with catalytic abilities. RNA-cleaving deoxyribozymes have been recognized as an efficient tool for detection of modifications in target RNAs and provide an alternative to traditional and modern methods for detection of ribose or nucleobase methylation. However, there are only few examples of DNA enzymes that specifically reveal the presence of a certain type of modification, including N6-methyladenosine, and the knowledge about how DNA enzymes recognize modified RNAs is still extremely limited. Therefore, DNA enzymes cannot be easily engineered for the analysis of desired RNA modifications, but are instead identified by in vitro selection from random DNA libraries using synthetic modified RNA substrates. This protocol describes a general in vitro selection stagtegy to evolve new RNA-cleaving DNA enzymes that can efficiently differentiate modified RNA substrates from their unmodified counterpart.
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- 2022
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14. Analysis of Current–Voltage Characteristics in UV AlGaN Heterostructure FPAs
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K. O. Boltar, N. I. Iakovleva, A. V. Nikonov, and M. V. Sednev
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010302 applied physics ,Radiation ,Materials science ,business.industry ,020206 networking & telecommunications ,Heterojunction ,02 engineering and technology ,Chemical vapor deposition ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Photodiode ,law.invention ,law ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Sapphire ,Optoelectronics ,Metalorganic vapour phase epitaxy ,Electrical and Electronic Engineering ,business ,Molecular beam epitaxy ,Dark current ,Leakage (electronics) - Abstract
UV visible-blind and solar-blind 320 × 256 photodiode arrays based on AlxGa1 – xN heteroepitaxial structures (AlGaN HES) and sensitive in the near-ultraviolet range of 0.2–0.4 μm have been created and studied. The AlGaN HES were grown by organometallic vapor deposition (MOCVD) and molecular beam epitaxy (MBE) on sapphire substrates. To reduce structural defects, the state of the surface and the surface layer of epipolished sapphire substrates was investigated, and a finishing technology was developed. UV FPAs in the AlGaN HES were produced by ion etching. The dark current components for AlGaN photodiodes were simulated. The main dark current components, such as generation–recombination, shunting leakage, hopping conductivity, and Poole–Frenkel components, are calculated. The possibility of achieving photoelectric parameters on the level of the best foreign counterparts is demonstrated.
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- 2019
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15. Performance of Work on Infrastructure Facilities to be Eliminated after the Destruction of Chemical Weapons
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Yu. Ohotnikov and V. Sednev
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Engineering ,Chemical warfare ,Work (electrical) ,business.industry ,Applied Mathematics ,General Mathematics ,business ,Construction engineering - Abstract
The article considers the status of the issue of the destruction of chemical weapons in Russia, the composition, nature, characteristics and hazards of decommissioning and elimination of the consequences of the activities of the former facility for the destruction of chemical weapons.
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- 2019
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16. RNA-Cleaving Deoxyribozymes Differentiate Methylated Cytidine Isomers in RNA
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Carina Stiller, Claudia Höbartner, Maksim V. Sednev, and Anam Liaqat
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Deoxyribozyme ,Cytidine ,site-specific RNA cleavage ,Cleavage (embryo) ,01 natural sciences ,Catalysis ,Substrate Specificity ,03 medical and health sciences ,chemistry.chemical_compound ,Epitranscriptomics ,Epigenetics ,Base Pairing ,030304 developmental biology ,RNA Cleavage ,0303 health sciences ,010405 organic chemistry ,Communication ,RNA ,General Medicine ,DNA, Catalytic ,General Chemistry ,RNA modification ,Communications ,In vitro ,0104 chemical sciences ,chemistry ,Biochemistry ,RNA Modification | Hot Paper ,in vitro selection ,Nucleic Acid Conformation ,deoxyribozymes ,epitranscriptomics ,DNA ,ddc:547 - Abstract
Deoxyribozymes are emerging as modification‐specific endonucleases for the analysis of epigenetic RNA modifications. Here, we report RNA‐cleaving deoxyribozymes that differentially respond to the presence of natural methylated cytidines, 3‐methylcytidine (m3C), N 4‐methylcytidine (m4C), and 5‐methylcytidine (m5C), respectively. Using in vitro selection, we found several DNA catalysts, which are selectively activated by only one of the three cytidine isomers, and display 10‐ to 30‐fold accelerated cleavage of their target m3C‐, m4C‐ or m5C‐modified RNA. An additional deoxyribozyme is strongly inhibited by any of the three methylcytidines, but effectively cleaves unmodified RNA. The mXC‐detecting deoxyribozymes are programmable for the interrogation of natural RNAs of interest, as demonstrated for human mitochondrial tRNAs containing known m3C and m5C sites. The results underline the potential of synthetic functional DNA to shape highly selective active sites., In vitro selected deoxyribozymes respond to the presence of methylcytidines m3C, m4C and m5C in RNA with either enhanced or strongly diminished cleavage rates, and thereby directly reveal the presence of the modified cytidines in target RNA.
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- 2021
17. Everlasting rhodamine dyes and true deciding factors in their STED microscopy performance
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Sergey M. Borisov, Kirill Kolmakov, Franziska R. Winter, Subhabrata Ghosh, Maksim V. Sednev, and Alexey V. Nizovtsev
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Rhodamine ,chemistry.chemical_compound ,Aqueous solution ,010405 organic chemistry ,Chemistry ,STED microscopy ,Physical and Theoretical Chemistry ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Photobleaching ,Fluorescence ,0104 chemical sciences - Abstract
The authors took an independent and closer look at the family of red-emitting rhodamine dyes known for a decade due to their excellent performance in STED microscopy. After the family was further extended, the true grounds of this performance became clear. Small-molecule protective agents and/or auxiliary groups were attached at two different sites of the dye's scaffold. Thus, a rhodamine core, which is already quite photostable as it is, and an intramolecular stabilizer – a 4-nitrobenzyl or a 4-nitrobenzylthio group were combined to give potentially “everlasting dyes”. The fluorescence quantum yields (Φf) and the fluorescence lifetimes (τ) of the modified dyes were thoroughly measured with comparison to those of the parent dyes. The correlation of their STED performance with photostability and fluorescence color stability under illumination in water were explored. Unexpectedly, the anaerobic GSDIM (GOC) buffer proved unhelpful with respect to STED performance. It was demonstrated that, even dyes with a Φf of only 14–17% allow STED imaging with a sufficient photon budget and good signal-to-noise ratio. For the dyes with photostabilizing groups (PSG) the Φf values are 4–5 times lower than in the reference dyes, and lifetimes τ are also strongly reduced. Noteworthy are very high fluorescence color stability and constant or even increasing fluorescence signal under photobleaching in bulk aqueous solutions, which suggests a sacrificing role of the 4-nitrobenzyl-containing moieties. Straightforward and improved recipes for “last-minute” modifications and preparations of “self-healing” red-emitting fluorescent tags are described.
- Published
- 2020
18. Machine learning of reverse transcription signatures of variegated polymerases allows mapping and discrimination of methylated purines in limited transcriptomes
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Thomas Kemmer, Christoph Falschlunger, Guillaume Bec, Virginie Marchand, Ronald Micura, Claudia Höbartner, Yuri Motorin, Mark Helm, Lukas Schmidt, Maksim V. Sednev, Stephan Werner, Eric Ennifar, Andreas Hildebrandt, Johannes Gutenberg - Universität Mainz (JGU), Ingénierie, Biologie et Santé en Lorraine (IBSLor), Université de Lorraine (UL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Leopold Franzens Universität Innsbruck - University of Innsbruck, University of Würzburg, Institut de biologie moléculaire et cellulaire (IBMC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), GONNET, JULIE, Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), and Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)
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Adenosine ,AcademicSubjects/SCI00010 ,Machine learning ,computer.software_genre ,[SDV.BBM.BM] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology ,Methylation ,Machine Learning ,03 medical and health sciences ,0302 clinical medicine ,Complementary DNA ,[SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN] ,Genetics ,Molecular Biology ,Polymerase ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,Oligoribonucleotides ,Guanosine ,biology ,business.industry ,RNA-Directed DNA Polymerase ,RNA ,[SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology ,Reverse Transcription ,Reverse transcriptase ,Enzyme ,chemistry ,Transfer RNA ,biology.protein ,[SDV.BBM.GTP] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN] ,Artificial intelligence ,Transcriptome ,business ,computer ,030217 neurology & neurosurgery - Abstract
Reverse transcription (RT) of RNA templates containing RNA modifications leads to synthesis of cDNA containing information on the modification in the form of misincorporation, arrest, or nucleotide skipping events. A compilation of such events from multiple cDNAs represents an RT-signature that is typical for a given modification, but, as we show here, depends also on the reverse transcriptase enzyme. A comparison of 13 different enzymes revealed a range of RT-signatures, with individual enzymes exhibiting average arrest rates between 20 and 75%, as well as average misincorporation rates between 30 and 75% in the read-through cDNA. Using RT-signatures from individual enzymes to train a random forest model as a machine learning regimen for prediction of modifications, we found strongly variegated success rates for the prediction of methylated purines, as exemplified with N1-methyladenosine (m1A). Among the 13 enzymes, a correlation was found between read length, misincorporation, and prediction success. Inversely, low average read length was correlated to high arrest rate and lower prediction success. The three most successful polymerases were then applied to the characterization of RT-signatures of other methylated purines. Guanosines featuring methyl groups on the Watson-Crick face were identified with high confidence, but discrimination between m1G and m22G was only partially successful. In summary, the results suggest that, given sufficient coverage and a set of specifically optimized reaction conditions for reverse transcription, all RNA modifications that impede Watson-Crick bonds can be distinguished by their RT-signature.
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- 2020
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19. NOseq: amplicon sequencing evaluation method for RNA m6A sites after chemical deamination
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Jean-Yves Roignant, Maksim V. Sednev, Andreas Hildebrandt, Tina Lence, Florian Pichot, Mark Helm, Aurellia Galliot, Virginie Marchand, Thomas Kemmer, Julian König, Yuri Motorin, Claudia Höbartner, Stephan Werner, GONNET, JULIE, Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), Ingénierie, Biologie et Santé en Lorraine (IBSLor), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), University of Würzburg, Institute of Molecular Biology (IMB), Center for Integrative Genomics - Institute of Bioinformatics, Génopode (CIG), Swiss Institute of Bioinformatics [Lausanne] (SIB), Université de Lausanne = University of Lausanne (UNIL)-Université de Lausanne = University of Lausanne (UNIL), Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Johannes Gutenberg - Universität Mainz (JGU), Université de Lorraine (UL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), and Université de Lausanne (UNIL)-Université de Lausanne (UNIL)
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Adenosine ,Sequence analysis ,AcademicSubjects/SCI00010 ,Bisulfite sequencing ,Deamination ,Adenosine/analogs & derivatives ,Adenosine/analysis ,Algorithms ,Animals ,Chromatography, Liquid ,Drosophila melanogaster/genetics ,HEK293 Cells ,HeLa Cells ,High-Throughput Nucleotide Sequencing/methods ,Humans ,RNA/chemistry ,RNA, Long Noncoding/chemistry ,RNA, Messenger/chemistry ,RNA, Ribosomal, 18S/chemistry ,Sequence Alignment ,Sequence Analysis, RNA/methods ,Tandem Mass Spectrometry ,Sequence alignment ,Computational biology ,Biology ,010402 general chemistry ,[SDV.BBM.BM] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology ,01 natural sciences ,Transcriptome ,03 medical and health sciences ,Narese/13 ,[SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN] ,Genetics ,RNA, Ribosomal, 18S ,RNA, Messenger ,ComputingMilieux_MISCELLANEOUS ,030304 developmental biology ,0303 health sciences ,Sequence Analysis, RNA ,RNA ,High-Throughput Nucleotide Sequencing ,[SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology ,Amplicon ,Ribosomal RNA ,0104 chemical sciences ,Drosophila melanogaster ,Methods Online ,[SDV.BBM.GTP] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN] ,RNA, Long Noncoding - Abstract
Methods for the detection of m6A by RNA-Seq technologies are increasingly sought after. We here present NOseq, a method to detect m6A residues in defined amplicons by virtue of their resistance to chemical deamination, effected by nitrous acid. Partial deamination in NOseq affects all exocyclic amino groups present in nucleobases and thus also changes sequence information. The method uses a mapping algorithm specifically adapted to the sequence degeneration caused by deamination events. Thus, m6A sites with partial modification levels of ∼50% were detected in defined amplicons, and this threshold can be lowered to ∼10% by combination with m6A immunoprecipitation. NOseq faithfully detected known m6A sites in human rRNA, and the long non-coding RNA MALAT1, and positively validated several m6A candidate sites, drawn from miCLIP data with an m6A antibody, in the transcriptome of Drosophila melanogaster. Conceptually related to bisulfite sequencing, NOseq presents a novel amplicon-based sequencing approach for the validation of m6A sites in defined sequences.
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- 2020
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20. N 6‐isopentenyladenosine in RNA determines the cleavage site of endonuclease deoxyribozymes
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Claudia Höbartner, Anam Liaqat, Maksim V. Sednev, Carina Stiller, and Manuela Michel
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TRNA modification ,Deoxyribozyme ,010402 general chemistry ,site-specific RNA cleavage ,01 natural sciences ,Catalysis ,Substrate Specificity ,03 medical and health sciences ,chemistry.chemical_compound ,Endonuclease ,Isopentenyladenosine ,RNA, Transfer ,Epitranscriptomics ,RNA Processing, Post-Transcriptional ,Research Articles ,030304 developmental biology ,RNA Cleavage ,0303 health sciences ,biology ,010405 organic chemistry ,Active site ,RNA ,General Medicine ,General Chemistry ,DNAzymes | Hot Paper ,DNA, Catalytic ,RNA modification ,0104 chemical sciences ,chemistry ,Biochemistry ,biology.protein ,in vitro selection ,Biocatalysis ,deoxyribozymes ,epitranscriptomics ,DNA ,ddc:547 ,Research Article - Abstract
RNA‐cleaving deoxyribozymes can serve as selective sensors and catalysts to examine the modification state of RNA. However, site‐specific endonuclease deoxyribozymes that selectively cleave post‐transcriptionally modified RNA are extremely rare and their specificity over unmodified RNA is low. We report that the native tRNA modification N6‐isopentenyladenosine (i6A) strongly enhances the specificity and has the power to reconfigure the active site of an RNA‐cleaving deoxyribozyme. Using in vitro selection, we identified a DNA enzyme that cleaves i6A‐modified RNA at least 2500‐fold faster than unmodified RNA. Another deoxyribozyme shows unique and unprecedented behaviour by shifting its cleavage site in the presence of the i6A RNA modification. Together with deoxyribozymes that are strongly inhibited by i6A, these results highlight that post‐transcriptional RNA modifications modulate the catalytic activity of DNA in various intricate ways., The natural tRNA modification i6A carries an isopentenyl (prenyl) group at the N 6 position of adenine. This modified nucleotide finetunes the active site of RNA‐cleaving deoxyribozymes, resulting in a distinct shift of the cleavage site. DNA catalysts are reported to exclusively cut post‐transcriptionally modified RNAs.
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- 2020
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21. N 6 ‐Methyladenosine‐Sensitive RNA‐Cleaving Deoxyribozymes
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Maksim V. Sednev, Volodymyr Mykhailiuk, Priyanka Choudhury, Julia Halang, Katherine E. Sloan, Markus T. Bohnsack, and Claudia Höbartner
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0301 basic medicine ,03 medical and health sciences ,030104 developmental biology ,General Medicine ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences - Published
- 2018
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22. Current–Voltage Characteristics of n-B-p Structures with Absorbing In0.53Ga0.47As Layer
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M. V. Sednev, K. O. Boltar, N. A. Irodov, and S. S. Demidov
- Subjects
010302 applied physics ,Radiation ,Materials science ,business.industry ,Infrared ,Photodetector ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Epitaxy ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Photodiode ,law.invention ,Planar ,law ,0103 physical sciences ,Optoelectronics ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Layer (electronics) ,Dark current - Abstract
A topical problem of photoelectronics is the development of array photodetector devices of the near infrared spectral range based on the InxGa1–xAs/InP epitaxial layers of the megapixel format. In this paper, we present the results of studies of current–voltage characteristics of photosensitive elements in arrays of the 320 × 256 format with a step of 30 μm based on heteroepitaxial structures with an InGaAs absorbing layer on InP short-wave infrared substrates. Arrays of photosensitive elements (PSEs) are fabricated using planar, mesa, and mesa planar technologies based on nB(Al0.48In0.52As)p-structures. In arrays produced using the mesa planar technology based on nB(Al0.48In0.52As)p-structures, small dark current and ampere–watt sensitivity to IR radiation of the 1–1.7 μm range are shown to combine successfully at low bias voltages. Electrophysical parameters of functional layers of initial heteroepitaxial n-B-p structures affect efficiently the dark currents and ampere–watt sensitivity of the array elements. Based on these studies, parameters of the n-B(Al0.48In0.52As) functional layers of p-structures were optimized and high-efficiency photodiode arrays of the 320 × 256 format with a step of 30 μm and structures of the 640 × 512 format with a step of 15 μm were fabricated with a defectiveness not exceeding 0.5%.
- Published
- 2018
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23. WAYS OF IMPROVING POWER SUPPLY RELIABILITY FOR RURAL CONSUMERS
- Author
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V. Sednev
- Subjects
Computer science ,Reliability (statistics) ,Reliability engineering ,Power (physics) - Published
- 2018
- Full Text
- View/download PDF
24. Study of Photodiodes Based on the InGaAs Structure with a Boundary Wavelength of 2.06 μm
- Author
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A. A. Marmalyuk, M. V. Sednev, N. A. Irodov, K. O. Boltar, Yu. L. Ryaboshtan, and Maxim A. Ladugin
- Subjects
Radiation ,Materials science ,business.industry ,Doping ,Condensed Matter Physics ,Epitaxy ,Spectral line ,Electronic, Optical and Magnetic Materials ,Photodiode ,law.invention ,Wavelength ,Photosensitivity ,law ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Layer (electronics) ,Diode - Abstract
I–V characteristics and spectral photosensitivities of photodiodes based on epitaxially grown hydrides of metal-organic compounds (MOC-hydride epitaxy) of epitaxial structures with the In0.67Ga0.33As absorbing layer doped with Zn on the InP substrates are studied. The photodiodes are fabricated using the mesatechnology. The long-wavelength boundary of the spectral photosensitivity of diodes measured at half-maximum is 2.06 μm at room temperature. Photosensitivity spectra are studied in a temperature interval of 230–300 K.
- Published
- 2019
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25. Analysis of characteristics of photodetectors based on InGaAs heteroepitaxial structures for 3D imaging
- Author
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M. V. Sednev, A. V. Nikonov, K. O. Boltar, and N. I. Iakovleva
- Subjects
Radiation ,Materials science ,Band gap ,business.industry ,Photodetector ,Heterojunction ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Epitaxy ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Photodiode ,law.invention ,010309 optics ,Barrier layer ,law ,0103 physical sciences ,Valence band ,Optoelectronics ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Dark current - Abstract
The 320 × 256 focal plane arrays based on р + -B–n-N + tetralayer heterostructures with a wide-gap barrier layer have been investigated. The heterostructures with a narrow-gap n-InGaAs absorbing layer were grown by means of metalorganic vapor phase epitaxy on InP substrates. The band discontinuity between the In0.53Ga0.47As absorbing layer and the In0.52Al0.48As barrier layer is removed by growing a thin four-component n-AlInGaAs layer with the bandgap gradient variation. Delta-doped layers included into the heterostructures make it possible to lower the barrier in the valence band and eliminate the nonmonotonicity of energy levels. The experimental study of the dark current has been performed. It has been revealed that the average value of the dark current does not exceed 10 fA for the photodiode arrays with a pitch of 30 μm.
- Published
- 2017
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26. Experience of minimally invasive treatment for early rectal cancer
- Author
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E. S. Savicheva, S. V. Vasil’ev, A. V. Sednev, D. E. Popov, A. V. Semenov, A. N. Klimenko, and E. V. Smirnova
- Subjects
transanal endoscopic microsurgery ,medicine.medical_specialty ,Colorectal cancer ,business.industry ,medicine ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,early rectal cancer ,local excision ,endorectal ultrasound ,medicine.disease ,business ,RC254-282 ,Surgery - Abstract
Objective. The aim of this study is to evaluate the experience with minimally invasive transanal operations and to improve treatment results in patients with early rectal cancer; to assess the accuracy of endorectal ultrasound (ERUS) in preoperative staging of rectal cancer. Materials and methods. The present clinical trial includes 38 selected patients who were underwent minimally invasive transanal procedures for early rectal cancers. 22 (58 %) patients were operated by transanal endoscopic microsurgery, 16 (42 %) were underwent transanal local excision. The study population consisted of 20 men and 18 women; average age was 64 (range 42–84) years. The main outcome measures included the operation time, the intra- and postoperative complication rate, negative microscopic margin rate, specimen fragmentation rate, oncological results (local recurrence and distant metastasis rate). Comparison of ERUS preoperative staging and pathological staging was performed to identify the accuracy of ERUS. The postoperative surveillance protocol was applied to all patients. Results. The median operative time was 56 (30–110) minutes. Postoperative complications occurred in 2 patients (5.2 %). There was no mortality. All pathological specimens were removed en block without fragmentation. Final histology revealed pTis – 10 (26 %), pT1sm1 – 9 (24 %), pT1sm2 – 12 (32 %), pT1sm3 – 5 (13 %) and pT2 – 2 (5 %) adenocarcinomas with negative resection margins (R0). The overall accuracy of ERUS for preoperative T stage was 78.9 %; for Tis was 80.0 % and for T1 – 85.0 %. All 7 patients in the pT1sm3 and pT2 groups were offered immediate radical surgery or adjuvant chemoradiotherapy. The follow-up period was from 5 to 60 (median 36) months. There was one local recurrence (2.6 %) in 6 months after local excision in a patient with pT1sm3. This patient underwent total mesorectumectomy. Conclusions. Selected patients with “low-risk” early rectal cancer and favorable features may be effectively treated with minimally invasive transanal operations without jeopardizing long-term oncological results. The lack of lymphadenectomy represents the main concern of this approach for the treatment of rectal cancer. Further follow-up is necessary. Preoperative ERUS has a good accuracy with pathologic T stage and can guide transanal procedure in early rectal cancer.
- Published
- 2017
27. Short-wavelength infrared array avalanche photodetectors on the basis of InGaAs heteroepitaxial structures
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N. I. Iakovleva, A. I. Patrashin, N. A. Irodov, K. O. Boltar, and M. V. Sednev
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Radiation ,Materials science ,Infrared ,business.industry ,Photodetector ,Heterojunction ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Avalanche photodiode ,Epitaxy ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Photodiode ,law.invention ,010309 optics ,Optics ,law ,0103 physical sciences ,Optoelectronics ,Metalorganic vapour phase epitaxy ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Absorption (electromagnetic radiation) - Abstract
SWIR ADP 320 × 256 FPAs based on p–i–n photodiodes in InGaAs heterostructures have been developed and investigated. The typical InGaAs/InP PIN heterostructures are formed by Metal Organic Vapor Phase Epitaxy (MOVPE) on n + type InP substrates. The InGaAs/InP PIN photodiodes performance have been estimated by measuring current-voltage characteristics. APD arrays are designed using a mesa-passivated avalanche photodiode device array of p–i–n junctions in heterostructure with common absorption and multiplication regions. The optimal operating point for managing avalanche application depended on various factors has been started at 15 V bias and the multiplication coefficient was of 2–4.
- Published
- 2016
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28. Characteristics of heteroepitaxial structures Al x Ga1–x N for p–i–n diode focal plane arrays
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Yu. P. Sharonov, K. O. Boltar, D. V. Smirnov, and M. V. Sednev
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Radiation ,Materials science ,Argon ,business.industry ,chemistry.chemical_element ,Photoresist ,Condensed Matter Physics ,Epitaxy ,Ion source ,Electronic, Optical and Magnetic Materials ,Ion ,Cardinal point ,Optics ,chemistry ,Etching (microfabrication) ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Diode - Abstract
Mesaelements of the focal plane array (FPA) of p–i–n diodes based on AlxGa1–xN for p–i–n heteroepitaxial structures (HESs) grown by the molecular-beam epitaxy and hydride epitaxy methods with the use of metalorganic compounds are formed. Elements of 320 × 256 FPAs with a pitch of 30 μm are separated by means of ion-beam etching through a photoresist mask in the argon ion stream produced by the Kaufmann ion source in a vacuum plant. To determine the required etching depth, contact profilometry and ultraviolet spectrophotometry methods allowing one to determine positions of the n-layer and sufficient etching depth of the sample are used. The thickness accuracy of the HES functional layers stated in manufacturer’s certificates does not exceed 28%. Rates of ion-beam etching of AlxGa1–xN for p–i–n layers with different compositions are determined.
- Published
- 2016
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29. ACTIVITY JUSTIFICATION METHODOLOGY FOR ELECTRIC POWER SAFETY PROVISION OF THE RUSSIAN FEDERATION SUBJECTS UNDER DIFFERENT OPERATION REGIMES OF THE RUSSIAN UNIFIED STATE SYSTEM OF PREVENTION AND RESPONSE TO EMERGENCY SITUATIONS
- Author
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A. Smurov and V. Sednev
- Subjects
State system ,Risk analysis (engineering) ,Russian federation ,Electric power ,Business ,Emergency situations - Published
- 2016
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30. ENGINEERING SOLUTIONS TO IMPROVE SETTLEMENT FIRE SAFETY IN WINTER
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V. Sednev and N. Teterina
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Settlement (structural) ,Forensic engineering ,Environmental science ,Fire safety - Published
- 2016
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31. N
- Author
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Maksim V, Sednev, Volodymyr, Mykhailiuk, Priyanka, Choudhury, Julia, Halang, Katherine E, Sloan, Markus T, Bohnsack, and Claudia, Höbartner
- Subjects
RNA Cleavage ,Adenosine ,Base Sequence ,Nucleic Acid Conformation ,RNA ,DNA, Catalytic ,Methylation ,Substrate Specificity - Abstract
Deoxyribozymes are synthetic enzymes made of DNA that can catalyze the cleavage or formation of phosphodiester bonds and are useful tools for RNA biochemistry. Herein, we report new RNA-cleaving deoxyribozymes to interrogate the methylation status of target RNAs, thereby providing an alternative method for the biochemical validation of RNA methylation sites containing N
- Published
- 2018
32. PONy Dyes: Direct Addition of P(III) Nucleophiles to Organic Fluorophores
- Author
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Heydar Shojaei, Alexey N. Butkevich, Vladimir N. Belov, Stefan W. Hell, and Maksim V. Sednev
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Nucleophilic addition ,010405 organic chemistry ,Organic Chemistry ,Cationic polymerization ,Thio ,Phosphinate ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Phosphonate ,0104 chemical sciences ,chemistry.chemical_compound ,Nucleophile ,chemistry ,Polymer chemistry ,Physical and Theoretical Chemistry ,Absorption (chemistry) ,BODIPY - Abstract
Nucleophilic addition of phosphinic acid, phosphites, sodium dialkyl phosphites, phosphoramidites, phosphinites, and phosphonites to highly polarized or cationic fluorophores, followed by oxidation, results in new “PONy” dyes with auxochromic phosphinate, phosphonate, or phosphonamidate groups. The reaction was applied to a wide variety of coumarins, (thio)pyronins, and N-alkylacridinium and 5,6-dihydrobenzo[c]xanthen-12-ium salts as well as a meso-chlorinated BODIPY to provide compact dyes with red-shifted absorption and emission bands and Stokes shifts up to 8200 cm–1.
- Published
- 2018
33. N 6 -Methyladenosine-Sensitive RNA-Cleaving Deoxyribozymes
- Author
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Priyanka Choudhury, Volodymyr Mykhailiuk, Maksim V. Sednev, Katherine E. Sloan, Markus T. Bohnsack, Julia Halang, and Claudia Höbartner
- Subjects
0301 basic medicine ,RNA methylation ,Deoxyribozyme ,RNA ,General Chemistry ,RNA Biochemistry ,Catalysis ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,chemistry ,Biochemistry ,ddc:540 ,Phosphodiester bond ,Small nucleolar RNA ,N6-Methyladenosine ,DNA - Abstract
Deoxyribozymes are synthetic enzymes made of DNA that can catalyze the cleavage or formation of phosphodiester bonds and are useful tools for RNA biochemistry. Here we report new RNA-cleaving deoxyribozymes to interrogate the methylation status of target RNAs, thereby providing an alternative method for the biochemical validation of RNA methylation sites containing N\(^6\)-methyladenosine, which is the most wide-spread and extensively investigated natural RNA modification. Using in vitro selection from random DNA, we developed deoxyribozymes that are sensitive to the presence of N\(^6\)-methyladenosine in RNA near the cleavage site. One class of these DNA enzymes shows faster cleavage of methylated RNA, while others are strongly inhibited by the modified nucleotide. The general applicability of the new deoxyribozymes is demonstrated for several examples of natural RNA sequences, including a lncRNA and a set of C/D box snoRNAs, which have been suggested to contain m\(^6\)A as a regulatory element that influences RNA folding and protein binding.
- Published
- 2018
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34. 'Reduced' Coumarin Dyes with an O-Phosphorylated 2,2-Dimethyl-4-(hydroxymethyl)-1,2,3,4-tetrahydroquinoline Fragment: Synthesis, Spectra, and STED Microscopy
- Author
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Stefan W. Hell, Shamil Nizamov, Maksim V. Sednev, Vladimir N. Belov, Elke Hebisch, Mariano L. Bossi, Stephan E. Lehnart, and Holm Frauendorf
- Subjects
Stereochemistry ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,Aldehyde ,Catalysis ,chemistry.chemical_compound ,Betaine ,Coumarins ,Fluorescence microscope ,Hydroxymethyl ,heterocyclic compounds ,Carboxylate ,Phosphorylation ,Fluorescent Dyes ,chemistry.chemical_classification ,Bioconjugation ,010405 organic chemistry ,Organic Chemistry ,General Chemistry ,Coumarin ,Fluorescence ,0104 chemical sciences ,3. Good health ,chemistry ,Microscopy, Fluorescence ,Quinolines - Abstract
Large Stokes-shift coumarin dyes with an O-phosphorylated 4-(hydroxymethyl)-2,2-dimethyl-1,2,3,4-tetrahydroquinoline fragment emitting in the blue, green, and red regions of the visible spectrum were synthesized. For this purpose, N-substituted and O-protected 1,2-dihydro-7-hydroxy-2,2,4-trimethylquinoline was oxidized with SeO2 to the corresponding α,β-unsaturated aldehyde and then reduced with NaBH4 in a "one-pot" fashion to yield N-substituted and 7-O-protected 4-(hydroxymethyl)-7-hydroxy-2,2-dimethyl-1,2,3,4-tetrahydroquinoline as a common precursor to all the coumarin dyes reported here. The photophysical properties of the new dyes ("reduced coumarins") and 1,2-dihydroquinoline analogues (formal precursors) with a trisubstituted C=C bond were compared. The "reduced coumarins" were found to be more photoresistant and brighter than their 1,2-dihydroquinoline counterparts. Free carboxylate analogues, as well as their antibody conjugates (obtained from N-hydroxysuccinimidyl esters) were also prepared. All studied conjugates with secondary antibodies afforded high specificity and were suitable for fluorescence microscopy. The red-emitting coumarin dye bearing a betaine fragment at the C-3-position showed excellent performance in stimulation emission depletion (STED) microscopy.
- Published
- 2016
35. (Z)-1-alkylidene- and 1-arylmethylidene-5,5-dimethyl-3-oxopyrazolidin-1-ium-2-ides and their cycloaddition to N-arylmaleimides
- Author
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Rafael R. Kostikov, Yu. B. Koptelov, and M. V. Sednev
- Subjects
Steric effects ,chemistry.chemical_compound ,chemistry ,Concerted reaction ,Stereochemistry ,Organic Chemistry ,Substituent ,Phenyl group ,Maleimide ,Cycloaddition - Abstract
The reaction of (Z)-1-arylmethylidene-5,5-dimethyl-3-oxopyrazolidin-1-ium-2-ides with para-substituted N-arylmaleimides at 110°C is cis-stereoselective [cis/trans-adduct ratio ≥(9–10): 1]. Under analogous conditions, the conversion of (Z)-1-(2,6-dichlorophenylmethylidene)-5,5-dimethyl-3-oxopyrazolidin-1-ium-2-ide in the reaction with N-(4-methoxyphenyl)maleimide in 6-7 h did not exceed 1–2%. The cycloaddition of (Z)-1-ethylidene- and (Z)-1-(2-methylpropylidene)-5,5-dimethyl-3-oxopyrazolidin-1-ium-2-ides to N-arylmaleimides, regardless of the substituent in the phenyl group of the latter, gave preferentially the corresponding trans-adducts, which cannot be rationalized only by steric effect of substituents in terms of the concerted mechanism.
- Published
- 2012
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36. Masked red-emitting carbopyronine dyes with photosensitive 2-diazo-1-indanone caging group
- Author
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Christian A. Wurm, Maksim V. Sednev, Stefan W. Hell, Vladimir N. Belov, Kirill Kolmakov, and Mariano L. Bossi
- Subjects
Quantum yield ,CAGE COMPOUNDS ,Photochemistry ,Cell Line ,law.invention ,Optical microscope ,law ,Animals ,Pyronine ,Physical and Theoretical Chemistry ,Fluorescent Dyes ,Aza Compounds ,High contrast ,Photosensitizing Agents ,Molecular Structure ,Chemistry ,Otras Ciencias Químicas ,Ciencias Químicas ,Stereoisomerism ,Fluorescence ,Rats ,2-diazo-1-indanone ,CARBOPYRONINES Carbopyronines ,Indans ,SUPERRESOLUTION MICROSCOPY ,Linker ,CIENCIAS NATURALES Y EXACTAS ,Visible spectrum - Abstract
Caged near-IR emitting fluorescent dyes are in high demand in optical microscopy but up to now were unavailable. We discovered that the combination of a carbopyronine dye core and a photosensitive 2-diazo-1-indanone residue leads to masked near-IR emitting fluorescent dyes. Illumination of these caged dyes with either UV or visible light (λ < 420 nm) efficiently generates fluorescent compounds with absorption and emission at 635 nm and 660 nm, respectively. A high-yielding synthetic route with attractive possibilities for further dye design is described in detail. Good photostability, high contrast, and a large fluorescence quantum yield after uncaging are the most important features of the new compounds for non-invasive imaging in high-resolution optical microscopy. For use in immunolabelling the caged dyes were decorated with a (hydrophilic) linker and an (activated) carboxyl group. Fil: Kolmakov, Kirill. Max Planck Institute for Biophysical Chemistry; Alemania Fil: Wurm, Christian. Max Planck Institute for Biophysical Chemistry; Alemania Fil: Sednev, Maksim V.. Max Planck Institute for Biophysical Chemistry; Alemania Fil: Bossi, Mariano Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina. Max Planck Institute for Biophysical Chemistry; Alemania Fil: Belov, Vladimir N.. Max Planck Institute for Biophysical Chemistry; Alemania Fil: Hell, Stefan W.. Max Planck Institute for Biophysical Chemistry; Alemania
- Published
- 2012
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37. Stable azomethine imines derived from pyrazolidin-3-one and their cycloaddition to N-arylmaleimides
- Author
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Yu. B. Koptelov and M. V. Sednev
- Subjects
chemistry.chemical_compound ,Tetrazine ,chemistry ,Diaziridine ,Stereochemistry ,Aryl ,Organic Chemistry ,Pyrazole ,Maleimide ,Cycloaddition ,Cis–trans isomerism ,Adduct - Abstract
Reactions of (Z)-1-arylmethylidene-3-oxopyrazolidin-1-ium-2-ides (stable analogs of azomethine imines generated by thermal opening of the diaziridine fragment in 6-aryl-1,5-diazabicyclo[3.1.0]hexanes) with N-arylmaleimides having no ortho substituents in the aryl group are stereoselective: the products are mixtures of the corresponding cis and trans adducts, the latter prevailing (∼1.4–2.6: 1). trans Adducts are formed as the only products in the reactions with di-ortho-substituted N-arylmaleimides. (Z)-1-[(2,6-Dichlorophenyl) methylidene]-3-oxopyrazolidin-1-ium-2-ide reacts with both para- and ortho-substituted N-arylmaleimides to give exclusively trans adducts. Labile azomethine imines generated by thermolysis of 6-aryl-1,5-diazabicyclo[3.1.0]hexanes are likely to have Z configuration as well.
- Published
- 2011
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38. Cover Picture: N 6 ‐Methyladenosine‐Sensitive RNA‐Cleaving Deoxyribozymes (Angew. Chem. Int. Ed. 46/2018)
- Author
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Priyanka Choudhury, Volodymyr Mykhailiuk, Markus T. Bohnsack, Katherine E. Sloan, Claudia Höbartner, Maksim V. Sednev, and Julia Halang
- Subjects
010405 organic chemistry ,Chemistry ,Stereochemistry ,INT ,Deoxyribozyme ,RNA ,General Chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,RNA modification ,Cover (algebra) ,N6-Methyladenosine - Published
- 2018
- Full Text
- View/download PDF
39. New thin layer chromatography technique using a gas stream above the plate sorption layer
- Author
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K. V. Sednev and V. G. Berezkin
- Subjects
Radial chromatography ,Countercurrent chromatography ,Chromatography ,Column chromatography ,Chromatography detector ,Chemistry ,Supercritical fluid chromatography ,Analytical chemistry ,General Chemistry ,High performance thin layer chromatography ,High-performance liquid chromatography ,humanities ,Thin-layer chromatography - Abstract
Thin layer chromatography (TLC) is the simplest and a rather efficient version of liquid chromatography and is widely used in analytical practice. In Russia, thin layer chromatography is used in more than 10000 laboratories. Therefore, further development of this liquid chromatography technique and an increase in its resolution and quickness are of common interest. As a further development of TLC, in this study, for the control of the chromatographic process, a carrier gas stream was passed above the plate with the absorption layer directly during separation and this technique was experimentally substantiated. According to the common opinion of researchers who actively and fruitfully use TLC, a key drawback of this technique is the presence of a gas volume in contact with the sorption layer of the plate during the separation [1‐4]. However, useless things are those for which no useful application has been found as yet.
- Published
- 2008
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40. Symptom of stress incontinence: pathogenesis, differential diagnosis and treatment problems
- Author
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G. A. Savitskiy, О. V. Sednev, Е. К. Aylamazian, D. А. Niaury, and G. М. Ziyatdinova
- Subjects
Pathogenesis ,Stress incontinence ,medicine.medical_specialty ,business.industry ,Internal medicine ,medicine ,Obstetrics and Gynecology ,Differential diagnosis ,medicine.disease ,business - Abstract
The symptom of stress incontinence can be the manifestation of the organic and functional pathology of the bladder and urethra. Consequently, there is necessity of the differential approach to the choice of treatment methods. In present article, the problem of stress incontinence is discussed according to pathophysiological point of view.
- Published
- 2004
- Full Text
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41. Analysis of the surgery experience in correction of genitals prolapse realised in the kaliningrad regional centre of endo video surgery
- Author
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O. V. Sednev
- Subjects
Obstetrics and Gynecology - Abstract
The present work contains the analysis of the follow-upgenitals prolapse surgery carried out with the 56 patients in the Kaliningrad regional centre of endo video surgery within the 1998 - 2002. In process of the analysis we have made a comparative assessment of long-term effectiveness of a number of the operations practiced in our centre. We have shown the evolution frequency pattern of such postoperative complications as dysuria and pain syndrome due to the fixed structures tention, as well as prolapse relapse pattern depending on the applied correction technology. We have also shown lack of their dependance on the degree of prolapse evidence. In addition the author has outlined his point of view on the ways of decreasing the amount of relapses in the follow-upgenitals prolapse.
- Published
- 2003
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42. Effect of temperature on resistance of LEDs based on AlGaAs heterostructures to 60Co gamma radiation
- Author
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V V Sednev, P V Rubanov, and A. V. Gradoboev
- Subjects
History ,Materials science ,business.industry ,Annealing (metallurgy) ,Heterojunction ,Radiation ,On resistance ,Computer Science Applications ,Education ,Ionizing radiation ,law.invention ,law ,Optoelectronics ,Irradiation ,business ,Radiation resistance ,Light-emitting diode - Abstract
The paper presents the results obtained in the study of the change in the parameters of IR LEDs based on AlGaAs double heterostructures under 60Co gamma irradiation with regard to irradiation temperature. The study indicated several consecutive stages of LED emissive power lowering under ionizing radiation. Increased temperature during gamma irradiation enhances radiation resistance at the first stage due to radiation-stimulated defect annealing, which reduces relative contribution of the first stage to the overall emissive power lowering. It was found that in exposure at temperature more than 380 K, the first stage of LED emissive power lowering is completely eliminated. At the second stage, increase in resistance is caused by the decreased relative contribution of the less stable first stage to the overall emissive power lowering. The maximum resistance of LEDs to gamma radiation depends on radiation resistance of metal–semiconductor contacts.
- Published
- 2017
- Full Text
- View/download PDF
43. [Untitled]
- Author
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K. V. Sednev and A. R. Tsyganov
- Subjects
chemistry.chemical_classification ,Chromatography ,Aqueous solution ,Chemistry ,Sodium ,chemistry.chemical_element ,Surfaces and Interfaces ,Polymer ,Surface tension ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Adsorption ,Chemical engineering ,Tube (fluid conveyance) ,Physical and Theoretical Chemistry ,Sodium dodecyl sulfate ,Sulfate - Abstract
It was found that the hydrophobization of the inner surface of a tube offers the stabilization of films of nonfoaming aqueous solutions closing the cross section of the tube. Based on this phenomenon, a modification of the known method of determining adsorption at the solution surface based on the separation of foam films from the solution was proposed for extending the potentialities of this method to nonfoaming solutions. Adsorption of sodium dodecyl sulfate on the aqueous solution–air interface was investigated in the range of low concentrations, which earlier was not easily accessible to measurements by known methods.
- Published
- 2001
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44. [Untitled]
- Author
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A. R. Tsyganov and K. V. Sednev
- Subjects
Continuous operation ,Chemistry ,Bubble ,Mixing (process engineering) ,Mineralogy ,Surfaces and Interfaces ,Fractionation ,Mechanics ,Separation process ,Physics::Fluid Dynamics ,Cross section (physics) ,Colloid and Surface Chemistry ,Adsorption ,Scientific method ,Physical and Theoretical Chemistry - Abstract
The process of bubble separation of substances using large gas bubbles totally closing the cross section of the column was investigated. The use of such bubbles decreases the longitudinal mixing of the solution and drastically increases the separation efficiency. A mathematical model was proposed for describing this process in the batch and continuous operation conditions. The model was tested experimentally.
- Published
- 2001
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- View/download PDF
45. Carborhodol: A new hybrid fluorophore obtained by combination of fluorescein and carbopyronine dye cores
- Author
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Stefan W. Hell, Christian A. Wurm, Vladimir N. Belov, and Maksim V. Sednev
- Subjects
Fluorophore ,Biomedical Engineering ,Analytical chemistry ,Pharmaceutical Science ,Quantum yield ,Bioengineering ,Photochemistry ,Rhodamine ,symbols.namesake ,chemistry.chemical_compound ,Stokes shift ,Chlorocebus aethiops ,Animals ,Fluorescein ,Vero Cells ,Fluorescent Dyes ,Pharmacology ,Anthracenes ,Molecular Structure ,Organic Chemistry ,Fluorescence ,chemistry ,Yield (chemistry) ,symbols ,Absorption (chemistry) ,Biotechnology - Abstract
Asymmetric hybrid fluorophores are built from the structural elements of two (or even more) symmetric dyes and can develop valuable new features which their parents do not possess. A new hybrid carborhodol dye was obtained by the combination of fluorescein and carbopyronine fluorophores. The brightly fluorescent hybrid dye with a linker and reactive group was prepared in 12 steps with overall yield of 1.6%. In aqueous solutions, it has absorption and emission maxima at 586 and 613 nm, respectively. Antibodies labeled with a carborhodol dye possess broad absorption and emission bands so that the effective Stokes shift is increased (compared with small Stokes shifts of the parent dyes) and the fluorescence quantum yield of 39% at a degree of labeling of 5.2. Two samples of secondary antibodies labeled with carborhodol and the benchmark red-emitting rhodamine dye (KK114) were used in two-color imaging experiments with excitation at 514-532 (carborhodol dye) and 633-640 nm (KK114). When emitted light was detected above 650 nm, the novel carborhodol dye provided a lower crosstalk than spectrally similar emitters (e. g., Atto594; crosstalk 40-60% with KK114 under the same conditions). The optical resolution of ca. 80 nm was attained using the new dye in stimulated emission depleted (STED) microscopy. The relatively short fluorescence lifetime in conjugates with antibodies (τ = 1.2-1.6 ns) suggests the possibility of dual FLIM with numerous dyes having τ values in the range of 3-5 ns. All of these features make the carborhodol fluorophore a valuable addition to the family of the red-emitting fluorescent dyes.
- Published
- 2013
46. ChemInform Abstract: (Z)-1-Alkylidene- and 1-Arylmethylidene-5,5-dimethyl-3-oxopyrazolidin-1-ium-2-ides and Their Cycloaddition to N-Arylmaleimides
- Author
-
M. V. Sednev, Yu. B. Koptelov, and Rafael R. Kostikov
- Subjects
chemistry.chemical_classification ,chemistry ,General Medicine ,Medicinal chemistry ,Cycloaddition ,Alkyl - Abstract
Cycloaddition reaction of aryl-substituted compounds (I) with maleimides (II) is cis-stereoselective, whereas alkyl derivatives (IV) give preferentially the corresponding trans-adducts.
- Published
- 2012
- Full Text
- View/download PDF
47. Phosphorylated 3-heteroarylcoumarins and their use in fluorescence microscopy and nanoscopy
- Author
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Katrin I. Willig, Maksim V. Sednev, Vladimir N. Belov, Shamil Nizamov, and Stefan W. Hell
- Subjects
chemistry.chemical_classification ,Fluorophore ,Organic Chemistry ,Optical Imaging ,STED microscopy ,General Chemistry ,Photochemistry ,Aldehyde ,Fluorescence ,Catalysis ,chemistry.chemical_compound ,Organophosphorus Compounds ,chemistry ,Suzuki reaction ,Microscopy, Fluorescence ,Coumarins ,Microscopy ,Fluorescence microscope ,Quinolines ,heterocyclic compounds ,Phosphorylation ,Methyl group ,Fluorescent Dyes - Abstract
Photostable and bright fluorescent dyes with large Stokes shifts are widely used as markers in far-field optical microscopy, but the variety of useful dyes is limited. The present study introduces new 3-heteroaryl coumarins decorated with a primary phosphate group (OP(O)(OH)2) attached to C-4 in 2,2,4-trimethyl-1,2-dihydroquinoline fragment fused with the coumarin fluorophore. The general synthetic route is based on the Suzuki reaction of 3-bromocoumarines with hetarylboronic acids followed by oxidation of the methyl group at the C[DOUBLE BOND]C bond with SeO2 (to an aldehyde), reduction with NaBH4 (to an alcohol), and conversion into a primary phosphate. The 4 position in the coumarin system may be unsubstituted or bear a methyl group. Phosphorylated coumarins were found to have high fluorescence quantum yields in the free state and after conjugation with proteins (in aqueous buffers). In super-resolution light microscopy with stimulated emission depletion (STED), the new coumarin dyes provide an optical resolution of 40–60 nm with a low background signal. Due to their large Stokes shifts and high photostability, phosphorylated coumarins enable to combine multilabel imaging (using one detector and several excitation sources) with diffraction unlimited optical resolution.
- Published
- 2012
48. Introduction of electrochemically activated carbon dioxide in halogen-containing polymers
- Author
-
D. V. Sednev, V. E. Titov, and Vyacheslav G. Koshechko
- Subjects
inorganic chemicals ,chemistry.chemical_classification ,Electrolysis ,Inorganic chemistry ,General Chemistry ,Polymer ,Chloride ,law.invention ,Polyvinyl chloride ,chemistry.chemical_compound ,chemistry ,Carboxylation ,Bromide ,law ,Halogen ,medicine ,Electrochemical reduction of carbon dioxide ,medicine.drug - Abstract
The possibility of electrochemical carboxylation of halogen-containing polymers by using carbon dioxide has been shown on the example of polyvinyl chloride and polyvinyl bromide. The process proceeds via the substitution of halogen atoms by carboxylic groups; this leads to the formation of the corresponding polyacrylic acid copolymers. The influence of various factors (the nature of the medium and of the electrode materials, the electrolysis mode, etc.) on the degree of carboxylation of the polymers has been studied.
- Published
- 1994
- Full Text
- View/download PDF
49. ChemInform Abstract: Stable Azomethine Imines Derived from Pyrazolidin-3-one and Their Cycloaddition to N-Arylmaleimides
- Author
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M. V. Sednev and Yu. B. Koptelov
- Subjects
Chemistry ,General Medicine ,Medicinal chemistry ,Cycloaddition - Abstract
Reaction of stable (Z)-azomethine imines (I) and (VII) with N-arylmaleimides gives predominantly or exclusively trans-adducts.
- Published
- 2011
- Full Text
- View/download PDF
50. Electrochemical functionalization of organic compounds by ?small? molecules
- Author
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Vitaly D. Pokhodenko, D. V. Sednev, V. E. Titov, and Vyacheslav G. Koshechko
- Subjects
chemistry.chemical_classification ,Electrolysis ,General Chemistry ,Polymer ,Electrochemistry ,Small molecule ,law.invention ,Carboxylation ,chemistry ,law ,Reagent ,Nitrosation ,Organic chemistry ,Molecule - Abstract
The author's results and published data on the electrochemical insertion of “small” molecules (CO2, SO2, CS2, NO) into organic substrates are reviewed. Special attention is paid to the cathodic carboxylation of halogen-containing aliphatic and aromatic compounds, polymers, and olefins, the sulfonylation and dithiocarboxylation of Freons, and anodic nitrosation of amines. The probable mechanisms of such processes and the effects of the nature of the reagents and the electrolysis conditions on the composition and yields of the final reaction products are examined.
- Published
- 1993
- Full Text
- View/download PDF
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