259 research outputs found
A Comprehensive Study of N-Butyl-1H-Benzimidazole
Imidazole derivatives have found wide application in organic and medicinal chemistry. In particular, benzimidazoles have proven biological activity as antiviral, antimicrobial, and antitumor agents. In this work, we experimentally and theoretically investigated N-Butyl-1H-benzimidazole. It has been shown that the presence of a butyl substituent in the N position does not significantly affect the conjugation and structural organization of benzimidazole. The optimized molecular parameters were performed by the DFT/B3LYP method with 6-311++G(d,p) basis set. This level of theory shows excellent concurrence with the experimental data. The non-covalent interactions that existed within our compound N-Butyl-1H-benzimidazole were also analyzed by the AIM, RDG, ELF, and LOL topological methods. The color shades of the ELF and LOL maps confirm the presence of bonding and non-bonding electrons in N-Butyl-1H-benzimidazole. From DFT calculations, various methods such as molecular electrostatic potential (MEP), Fukui functions, Mulliken atomic charges, and frontier molecular orbital (HOMO-LUMO) were characterized. Furthermore, UV-Vis absorption and natural bond orbital (NBO) analysis were calculated. It is shown that the experimental and theoretical spectra of N-Butyl-1H-benzimidazole have a peak at 248 nm; in addition, the experimental spectrum has a peak near 295 nm. The NBO method shows that the delocalization of the aσ-electron from σ (C1–C2) is distributed into antibonding σ* (C1–C6), σ* (C1–N26), and σ* (C6–H11), which leads to stabilization energies of 4.63, 0.86, and 2.42 KJ/mol, respectively. Spectroscopic investigations of N-Butyl-1H-benzimidazole were carried out experimentally and theoretically to find FTIR vibrational spectra. © 2022 by the authors
Optimization of the Androgenesis Method in the In Vitro Culture of Anteneson the Basis ofT. AestivumHybrids
This study aimed to examine the regularities of the regenerationprocesses of haploid plants, the dependence of in vitro microspore morphogenesis in anther culture on optimization factors, and their efficiency in F1 hybrids of T. aestivumof different ecological and geographicorigin. It was found that heterosis contributed to an increased yield of haploid chlorophyll-bearing regenerants from hybrids obtained from the crossing of parental forms with different responsiveness to androclinia. Results were obtained for the complex optimization of the androgenesis method for the in vitro anther culture of T. aestivum, in order to create diploidized haploid lines (DHL) regardless of the influence of the genotype. The agroecological properties for a complex of economically useful traits were also assessed. DHLs were created that combined high yield (5.1-6.8 t / ha) with lodging resistance (straw height – 60-80 cm) and consistently high grain quality; these were characterized by increased resistance to major leaf diseases in comparison with the standard variety in the conditions of the Central Economic Region of the Non-Black Earth Zone of the Russian Federation.
Keywords: spring soft wheat, androgenesis, embyroidogenesis, callusogenesis, diploidized haploids, in vitro, yield and qualit
Catalytic sulfation of betulin with sulfamic acid : experiment and DFT calculation
Betulin is an important triterpenoid substance isolated from birch bark, which, together with its sulfates, exhibits important bioactive properties. We report on a newly developed method of betulin sulfation with sulfamic acid in pyridine in the presence of an Amberlyst(®)15 solid acid catalyst. It has been shown that this catalyst remains stable when being repeatedly (up to four cycles) used and ensures obtaining of sulfated betulin with a sulfur content of ~10%. The introduction of the sulfate group into the betulin molecule has been proven by Fourier-transform infrared, ultraviolet-visible, and nuclear magnetic resonance spectroscopy. The Fourier-transform infrared (FTIR) spectra contain absorption bands at 1249 and 835–841 cm(−1); in the UV spectra, the peak intensity decreases; and, in the nuclear magnetic resonance (NMR) spectra, of betulin disulfate, carbons С3 and С28 are completely shifted to the weak-field region (to 88.21 and 67.32 ppm, respectively) with respect to betulin. Using the potentiometric titration method, the product of acidity constants K(1) and K(2) of a solution of the betulin disulfate H(+) form has been found to be 3.86 × 10(–6) ± 0.004. It has been demonstrated by the thermal analysis that betulin and the betulin disulfate sodium salt are stable at temperatures of up to 240 and 220 °C, respectively. The density functional theory method has been used to obtain data on the most stable conformations, molecular electrostatic potential, frontier molecular orbitals, and mulliken atomic charges of betulin and betulin disulfate and to calculate the spectral characteristics of initial and sulfated betulin, which agree well with the experimental data
Monitoring of tritium purity during long-term circulation in the KATRIN test experiment LOOPINO using laser Raman spectroscopy
The gas circulation loop LOOPINO has been set up and commissioned at Tritium
Laboratory Karlsruhe (TLK) to perform Raman measurements of circulating tritium
mixtures under conditions similar to the inner loop system of the neutrino-mass
experiment KATRIN, which is currently under construction. A custom-made
interface is used to connect the tritium containing measurement cell, located
inside a glove box, with the Raman setup standing on the outside. A tritium
sample (purity > 95%, 20 kPa total pressure) was circulated in LOOPINO for more
than three weeks with a total throughput of 770 g of tritium. Compositional
changes in the sample and the formation of tritiated and deuterated methanes
CT_(4-n)X_n (X=H,D; n=0,1) were observed. Both effects are caused by hydrogen
isotope exchange reactions and gas-wall interactions, due to tritium {\beta}
decay. A precision of 0.1% was achieved for the monitoring of the T_2
Q_1-branch, which fulfills the requirements for the KATRIN experiment and
demonstrates the feasibility of high-precision Raman measurements with tritium
inside a glove box
To the Question of Assessing the Technical Condition of the Construction Structures of the Administrative Building Unfinished by the Construction in Platonovа st. In Minsk
Секция II : Строительные конструкции зданий и сооружений, современные методы расчета и проектированияВ статье приведены результаты обследования технического состояния строительных конструкций незавершенного строительством здания поликлиники для размещения стоматологического факультета БелГИУВ по ул. Платонова в г. Минске. В результате визуального и инструментального обследования строительных конструкций, выполненных поверочных расчетов и анализа полученных результатов сделаны выводы о техническом состоянии конструкций и даны соответствующие рекомендации.=The article presents the results of a survey of the technical condition of building structures under construction of the building of the clinic for placement of the Faculty of Dentistry BSMU on Platonovа st. in the city of Minsk. As a result of visual and instrumental examination of building structures, performed verification calculations and analysis of the results obtained, conclusions are made about the technical condition of structures and corresponding recommendations are given
To the Question of Assessing the Technical Condition of the Construction Structures of the Administrative Building Unfinished by the Construction in Platonovа st. In Minsk
Секция II : Строительные конструкции зданий и сооружений, современные методы расчета и проектированияВ статье приведены результаты обследования технического состояния строительных конструкций незавершенного строительством здания поликлиники для размещения стоматологического факультета БелГИУВ по ул. Платонова в г. Минске. В результате визуального и инструментального обследования строительных конструкций, выполненных поверочных расчетов и анализа полученных результатов сделаны выводы о техническом состоянии конструкций и даны соответствующие рекомендации.=The article presents the results of a survey of the technical condition of building structures under construction of the building of the clinic for placement of the Faculty of Dentistry BSMU on Platonovа st. in the city of Minsk. As a result of visual and instrumental examination of building structures, performed verification calculations and analysis of the results obtained, conclusions are made about the technical condition of structures and corresponding recommendations are given
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Improved Upper Limit on the Neutrino Mass from a Direct Kinematic Method by KATRIN.
We report on the neutrino mass measurement result from the first four-week science run of the Karlsruhe Tritium Neutrino experiment KATRIN in spring 2019. Beta-decay electrons from a high-purity gaseous molecular tritium source are energy analyzed by a high-resolution MAC-E filter. A fit of the integrated electron spectrum over a narrow interval around the kinematic end point at 18.57 keV gives an effective neutrino mass square value of (-1.0_{-1.1}^{+0.9}) eV^{2}. From this, we derive an upper limit of 1.1 eV (90% confidence level) on the absolute mass scale of neutrinos. This value coincides with the KATRIN sensitivity. It improves upon previous mass limits from kinematic measurements by almost a factor of 2 and provides model-independent input to cosmological studies of structure formation
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