Asymptotic expansion of the solution of the steady Stokes equation with variable viscosity in a two-dimensional tube structure

The Stokes equation with the varying viscosity is considered in a thin tube structure, i.e. in a connected union of thin rectangles with heights of order $\varepsilon<<1$ and with bases of order 1 with smoothened boundary. An asymptotic expansion of the solution is constructed: it contains some Poiseuille type flows in the channels (rectangles) with some boundary layers correctors in the neighborhoods of the bifurcations of the channels. The estimates for the difference of the exact solution and its asymptotic approximation are proved.Comment: 22 pages, 20 figure

Дослідження впливу солей 2-((4-R-3-(морфолінометилен)-4H-1,2,4-триазол-5-іл) тіо)ацетатних кислот на ріст і розвиток паростків кукурудзи

Topicality. Agricultural industry urgently requires new and effective growth stimulating remedies. 1,2,4-triazole derivatives have had exhibited themselves as active fungicides and growth stimulators and the salts of 2-(4-R-3-R1-1,2,4-triazole-5-yltio)acetic acid are quite promising in this aspect.Aim. To determine the impact on quality indicators of Galatea hybrid corn sprouts germination after the processing with solutions of 2-((4-R-3 (morfolinomethylen)-4H-1,2,4-triazole-5-yl)thio) acetic acid salts.Materials and methods. The objects of our research were 10 new substances derivative 1,2,4-triazole derivatives. Further it was studied the impact of these compounds on the performance and germination of the “Galatea” hybrid corn seed in 2016 harvest. We have used auxin as the study comparison and distilled water was used as a control.Results and discussion. The study had found that these compounds could differently influence on the growth and development of corn sprouts. It was mentioned that on the growth stimulating activity intensiveness can influence the replacement of amino group at the N4 nitrogen atom of 1,2,4-triazole cycle and the type of cation which is combined with acids.Conclusions. In the result of our experiment it was determined the prospects of further investigations of synthesized compounds as a growth stimulators and noted appropriateness of “structure action” dependences could be integrated into future research.Актуальность. Сельскохозяйственная промышленность остро нуждается в создании новых и эффективных ростстимулирующих средств. Производные 1,2,4-триазола уже успели проявить себя как активные стимуляторы роста и фунгициды, а соли 2-(4-R-3-R1-1,2,4-триазол-5-илтио)ацетатных кислот являются весьма перспективными в этом плане.Целью данных исследований является определение влияния на качественные показатели прорастания ростков кукурузы гибрида Галатея после их обработки растворами солей 2-((4-R-3-(морфолинометилен)-4H-1,2,4-триазол-5-ил)тио)ацетатных кислот.Материалы и методы. Объектами наших исследований были 10 новых веществ, производных 1,2,4-триазола. В дальнейшем проведено исследование влияния указанных соединений на показатели энергии прорас-тания и всхожести семян кукурузы гибрида «Галатея» урожая 2016 г. Как эталон исследования использовался ауксин, а контролем служила дистиллированная вода.Результаты и их обсуждение. В результате исследования установлено, что указанные соединения поразному способны влиять на рост и развитие ростков кукурузы. Отмечено, что на интенсивность ростстимулирующей активности влияют как заместители при N4 атоме азота 1,2,3,4-триазолового цикла, так и характер катиона, который связан с кислотами.Выводы. В результате эксперимента установлено перспективность дальнейших исследований синтезированных веществ в качестве ростстимуляторов, а отмеченные закономерности зависимости «структура-действие» могут быть интегрированы в дальнейшие исследования.Актуальність. Сільськогосподарська промисловість гостро потребує створення нових та ефективних ріст-стимулюючих засобів. Похідні 1,2,4-триазолу вже встигли проявити себе як активні стимулятори росту та фунгіциди, а солі 2-(4-R-3-R1-1,2,4-триазол-5-ілтіо)ацетатних кислот є досить перспективними в цьому плані.Метою даних досліджень є визначення впливу на якісні показники проростання паростків кукурудзи гібриду Галатея після їх обробки розчинами солей 2-((4-R-3-(морфолінометилен)-4H-1,2,4-триазол-5-іл)тіо)ацетатних кислот.Матеріали та методи. Об’єктами наших досліджень були 10 нових речовин, похідних 1,2,4-триазолу. В подальшому проведено дослідження впливу вказаних сполук на показники енергії проростання та схожості насіння кукурудзи гібриду «Галатея» врожаю 2016 р. Як еталон дослідження використовувався ауксин, а контролем слугувала дистильована вода.Результати та їх обговорення. В результаті проведеного дослідження встановлено, що вказані сполуки по-різному здатні впливати на ріст та розвиток паростків кукурудзи. Відмічено, що на інтенсивність рістстиму-люючої активності впливають як замісники за N4 атомом азоту 1,2,4-триазолового циклу, так і характер катіону зв’язаного з кислотами.Висновки. В результаті експерименту встановлено перспективність подальших досліджень синтезованих речовин в якості рістстимуляторів, а відмічені закономірності залежності «структура-дія» можуть бути інтегровані в подальші дослідження

Synthesis and properties of bis((4-R-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazol-3-yl)thio)alkanes

The aim of this work was the synthesis of bis((4-R-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazol-3-yl)thio)alkanes using available reagents and study of their properties. Matherial and methods. 4-R-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazol-3-thiol was used as an intermediate compound, obtained from methyl 2-(thiophen-2-yl)acetate. Its synthesis has been described in previous studies. During the bis((4-R-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazol-3-yl)thio)alkane moiety formation stage, dibromoalkanes (dibromomethane, dibromopropane, dibromobuthane) were used as secondary reagents. The reaction was conducted in propan-2-ol. The presence of reaction products has been confirmed applying spectral methods. Synthesis of bis((4-R-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazol-3-yl)thio)alkanes 0.01 M of the correspondent alkyl halide is added to the corresponding 3-(3-R-1,2,4-triazol-5-thiomethyl)-1,2,4-triazol-5-thione (0.01 M) in mixture of 0.01 mole NaОН and 30 mL of ethanol or propan-1-ol, and the mixture is boiled until the neutralization (during 3 hours reflux). The mixture is filtered, solvent is evaporated. White crystalline matter, practically insoluble in water, soluble in organic solvents. Compounds were purified by recrystallization from dimethylformamide-water mixture (1:1). Results. Distinction of compounds was confirmed by chromatography-mass-spectrometry. 1H NMR spectra of the obtained compounds were characterized by number of signals. The protons of alkylsulfide fragment resonate in a weak field appearing as multiplets at 3.12–3.07 ppm and 2.25–2.10 ppm. The protons of methyl group, which bond the heteroaromatic fragments together, resonate as a singlet at 3.92–3.87 ppm. Aromatic protons of thiophene fragments appear as multiplets at 6.95–6.78 and 6.99–7.20 ppm. The protons of methyl fragment of N-alkyl substituent appear as a multiplet at 4.21–3.98 ppm, protons of methyl fragment resonate as a triplet at 1.52–1.57 ppm. IR spectra of the studied compounds showed presence of C-S fragment, which appears as a band of molecular stretching at 693 cm-1. Stretching vibrations of С-H fragment of thiophene ring is observed at 715–693 cm-1. The CH2 fragment appears as strong stretching (at 2935–2905 cm-1 and 2865–2855 cm-1) and moderate bending vibrations (at 1493–1460 cm-1). Also recommended for “polymethylene fragment” are characteristic deformation vibrations at 730–720 cm-1. Symmetrical and asymmetrical bending at 1385–1380 and 1470–1465 cm-1characterize the presence of СН3 group. Preliminary screening of acute toxicity and biological activity parameters has been carried out. Conclusions. Nine compounds were obtained; their structures were confirmed.The characteristics of the synthesized compounds were assessed with computer processing using PASS online tool. The most promising compounds were selected for in vitro research. It was clarified during the analysis of results that the obtained compounds may exhibit various types of biological activities. The most probable effect predicted for the nine studied compounds is antimicrobial activity. 1,2,4-triazole, bis-derivatives, synthesis, IR spectroscopy, 1Н NMR spectroscopy, PASS-screenin

Похідні 4-(R-аміно)-5-(тіофен-2-ілметил)-4H-1,2,4-тріазол-3-тіолів, як перспективні протимікробні та протигрибкові речовини

This article contains the results antimicrobial and antifungal activity 3-(alkylthio)-5-(thiophene-2-ylmethyl)-4H-1,2,4-triazole-4-amines (1-6), N-R-eden-3-(nonylthio)-5-(thiophene-2-ylmethyl)-4H-1,2,4-triazole-4-amines (7-9) and 2-((4-amino-5-(thiophene-2-ylmethyl)-4H-1,2,4-triazole-3-yl)thio)-N’-R-acetohydra-zides are studied the results by the method of “serial dilutions”. Compound 6 and 20 show the same antifungal activity with comparing fluconazole. A substance 3 (MIC of 31.25 mg/ml) is the most active compound on S. Aureus bacteria which was studied among 3-(alkylthio)-5-(thiophene-2-ylmethyl)-4H-1,2,4-triazoles-4-amine (1-6). Replacing of hexyl radical in atom of sulfur to nonyl and injection in the molecule 3-(alkylthio)-5-(thiophene-2-ylmethyl)-4H-1,2,4-triazoles-4-amine 4-methoxybenzyl-iden substitute (9) led to increasing antimicrobial activity (MIC 15.6 mg/ml).Cтатья содержит результаты исследования противомикробного и противогрибкового действия 3-(алкилтио)-5-(тиофен-2-илметил)-4H-1,2,4-триазол-4-аминов (1-6), N-R-иден-3-(нонилтио)-5-(тиофен-2-илметил)-4H-1,2,4-триазол-4-аминов (7-9) и 2-((4-амино-5-(тиофен-2-илметил)-4H-1,2,4-триазол-3-ил)тио)-N’-R-ацетогидразидов методом серийных разведений. Соединения 6 и 20 проявляют одинаковую противогрибковую активность с препаратом сравнения флуконазолом. Наиболее активным соединением по бактерии S. Aureus среди исследованных 3-(алкилтио)-5-(тиофен-2-илметил)-4H-1,2,4-триазол-4-аминов (1-6) является вещество 3 (МИК31,25 мкг/мл). Замена гексильного радикала при атоме серы на нонильный и введение в молекулу 3-(алкилтио)-5-(тиофен-2-илметил)-4H-1,2,4-триазол-4-амина 4-метоксибензилиденового заместителя (9) приводит к повышению противомикробного действия (МИК 15,6 мкг/мл).Дана стаття містить результати дослідження протимікробної та протигрибкової дії 3-(алкілтіо)-5-(тіофен-2-ілметил)-4H-1,2,4-тріазол-4-амінів (1-6), N-R-іден-3-(нонілтіо)-5-(тіофен-2-ілметил)-4H-1,2,4-тріазол-4-амінів (7-9)  та 2-((4-аміно-5-(тіофен-2-ілметил)-4H-1,2,4-тріазол-3-іл)тіо)-N'-R-ацетогідразидів методом серійних розведень. Сполука 6 та 20 проявляє однакову протигрибкову активність з препаратом порівняння флуконазол. Найбільш активною сполукою щодо бактерії S. Aureus серед досліджених 3-(алкілтіо)-5-(тіофен-2-ілметил)-4H-1,2,4-тріазол-4-амінів (1-6) є речовина 3 (мінімальна інгібуюча концентрація 31,25 мкг/мл). Заміна гексильного радикалу при атомі Сульфуру на нонільний та введення в молекулу 3-(алкілтіо)-5-(тіофен-2-ілметил)-4H-1,2,4-тріазол-4-аміну 4-метоксибензиліденового замісника (9) призводить до підвищення протимікробної дії (МІК 15,6 мкг/мл)

Synthesis, physic and chemical properties of 2-(4-R-5-(thiophene-2-ylmethyl)-4h-1,2,4-triazole-3-ylthio)acetate acids and their salts

Derivatives of 1,2,4-triazole are inherent in various types of biological activity. They can be used as pesticide and medicinal drugs (anticonvulsants, analgetics, antitumor and antibacterial). In this regard the search of new methods of synthesis and investigation of biological activity of 2-(4-R-5-(thiophene-2-ylmethyl)-4H-1,2,4-triazole-3-ylthio)acetate acids and their salts is relevant nowadays. With the aim of finding the new biologically active compounds 2-(4-R-5-(thiophene-2-ylmethyl)-4H-1,2,4-triazole-3-ylthio)acetate acids and their salts are synthesized, where R is methyl, ethyl, phenyl. The interaction of 4-R-5-(thiophene-2-ylmethyl)-4H-1,2,4-triazole-3-thions with monochloracetate acid in the medium of i-propyl alcohol in the presence of an equivalent amount of alkali the corresponding 2-(4-R-5-(thiophene-2-ylmethyl)-4H-1,2,4 triazole-3-ylthio)acetate acids are obtained on the basis of which the corresponding salts of morpholine, dimethylamine, monoethanolamine, pteridine, ZnSO4 , CuSO4, NaOH and KOH are obtained and the structure of the received compounds was confirmed on the basis of the data of elemental, IR-, 1H-NMR-spectroscopy. The synthesis of 2-(4-R-5-(thiophene-2-ylmethyl)-4H-1,2,4-triazole-3-ylthio) acetate acids and their salts was conducted. With the help of modern physico-chemical methods: elemental analysis, IR, 1H-NMR-spectroscopy the structure of synthesized compounds, and their individuality by HPLC-MS is proved. In the IR spectrum of the compound 2-(4-phenyl-5-(thiophene-2-ylmethyl)-4H-1,2,4-triazole-3-ylthio)acetate acid Ic available band fluctuations groups characteristic for the nucleus of 1,2,4-triazole: NH– in the range of 3 400–3 100 cm-1,–C=N– – 1 690–1 620 cm-1. Also present band fluctuations groups –C–S– at 691 cm-1. Available band fluctuations characteristic of the group –CH2 within 1496.59 cm-1 and group –COO-H– – 1722.70 cm-1. This suggests the possibility to further study the biological action of the synthesized compounds

In silico evaluation of the pharmacodynamic component of the interaction of S-alkyl derivatives of 5-methyl-4-(p-tolyl)-1,2,4-triazole-3-thiol with some biological targets

Derivatives of 1,2,4-triazole open wide opportunities for modern and progressive scientists in the development of innovative medicines. These compounds are known for their variability and structural flexibility, which allows scientists to experiment and create new molecules with unique properties. The use of 1,2,4-triazole derivatives in the creation of drugs is based on their ability to interact with biological systems and molecular targets. These compounds can be aimed at regulating physiological processes, reducing manifestations of pathological conditions or enhancing necessary biological reactions. Directed modification of the structure of 1,2,4-triazole derivatives allows to create biologically active compounds with improved properties. The aim of the work was to study in silico and to evaluate the possible interaction of a virtual series of S-alkyl derivatives of 5-methyl-4-(p-tolyl)-1,2,4-triazole-3-thiol with some enzyme systems. Materials and methods. A computer method (molecular docking) for predicting and evaluating the interaction between a ligand molecule and a target protein structure. Ligand preparation was performed using MarvinSketch 6.3.0, Hyper Chem 8, and AutoDockTools-1.5.6 programs. Enzyme preparation involved the use of Discovery Studio 4.0 and AutoDockTools-1.5.6 software packages. Direct molecular docking was performed using the Vina program. Results. A virtual series of S-alkyl derivatives of 5-methyl-4-(p-tolyl)-1,2,4-triazole-3-thiol with the potential possibility of creating a biologically active substance has been constructed. Using the Vina software tool, the nature and number of amino acid residues of the active centers of model enzymes, with which the proposed ligands coordinate and bind, were determined. According to the results of docking studies, the predicted affinity for lanosterol-14α-demethylase was determined. The effect on the receptor tyrosine kinase of anaplastic lymphoma is somewhat inferior in terms of qualitative and quantitative indicators. Conclusions. Using the method of molecular docking, it was established that S-alkyl derivatives of 5-methyl-4-(p-tolyl)-1,2,4-triazole-3-thiol have a fairly significant potential for the manifestation of antifungal activity, which justifies the further synthesis of these compounds and more in-depth study of fungistatic and fungicidal properties. Docking results for anaplastic lymphoma kinase show little promise in the development of anticancer agents

Results of a search for 2β\beta-decay of 136^{136}Xe with high-pressure copper proportional counters in Baksan Neutrino Observatory

The experiment for the 2$\beta$-decay of $^{136}$Xe search with two high-pressure copper proportional counters has been held in Baksan neutrino observatory. The search for the process is based on comparison of spectra measured with natural and enriched xenon. No evidence has been found for 2$\beta$(2$\nu$)- and 2$\beta$(0$\nu$)-decay. The decay half lifetime limit based on data measured during 8000 h is T$_{1/2}$$\geq8.5\cdot10^{21}$yr for 2$\nu$-mode and T$_{1/2}$$\geq3.1\cdot10^{23}$yr for 0$\nu$-mode (90%C.L.).Comment: 9 pages, 8 figures; talk at the NANP'05 Conference; submitted to Phys. At. Nuc

Synthesis and study of the properties of derivatives 4-phenyl-5-(1H-pyrrol-2-yl)-4H-1,2,4-triazole-3-thiols

The successful use of drugs, derivatives of 1,2,4-triazole, creates the conditionsfor the production and investigation of properties of new derivatives of this heterocyclic system. The aim of this work was synthesis and study of physical and chemical properties of new derivatives of 1,2,4-triazole-3-thiol containing synthon of pyrrole. The object of the study was a 4-phenyl-5-(pyrrol-2-yl)-1,2,4-triazole-3-ylthio-R-carbothioamides. To achieve this goal it was necessary to solve following tasks: to conduct the selection of the optimum base structure to determine the most efficient way of chemical modification of the precursor of targeted synthesis, to carry out selection of necessary methods of synthesis, to investigate the physico-chemical properties and to set the structure of the obtained compounds. The synthesis of target products of the reaction was carried out using as starting material pyrrole, which with using the form non-catalytic form of reaction of the Fridel-Crafts was transformed into 2,2,2-trichloro-1-(pyrrol-2-yl), ethanol. The resulting material in the result of reaction of hydrazinolysis was converted into the pyrrol-2-carbohydrazide. The obtained intermediate product was used in the reaction of nucleophilic joining of phenylisothiocyanate with subsequent intramolecular alkaline heterocyclization. Synthesized thiol was used in the reaction of alkylation. The structure of the obtained substances are confirmed by using elemental analysis, 1H-NMR-spectroscopy, and their individuality – chromatographic methods of analysis. The resulting substances are an interesting object for further studies, especially biological activity

Quantitative determination of methanol and propanol-2 in tinctures and extracts using head-space gas chromatography in comparison with method of vaporization of liquid in GC inlet

The aim of this work was to compare sensitivity of methods for determination of methanol and propanol-2 contents in tinctures and extracts. Materials and methods. Two methods suggested in the State Pharmacopoeia of Ukraine for determination of the above mentioned compounds in liquid medicines were used, specifically: head-space gas-chromatography (method A) and classic gas chromatography (method B) with common injection technique. The research was conducted on one of the most popular medicinal products based on ethanol extracts of herbal drugs: echinacea (Tinctura Echinaceae), hawthorn (Tinctura Crataegi), and motherwort tinctures (Tinctura Leonuri). All medicines used were manufactured at pharmaceutical factory “VIOLA” (Zaporizhzhia, Ukraine). Substance analysis was held on gas chromatograph Agilent 7890B (USA) coupled to head – space sampler DANI HSS 86.50 Plus (Italy). Compounds were separated on J&W Agilent DB-624 (USA) column. In the study quantitative contents of methanol and propanol-2 were evaluated in tinctures and extracts using methods of head – space gas chromatography and liquid evaporation in the GC inlet (common injection technique), sensitivities of both methods were compared due to signal-to-noise levels. Statistical parameters of the obtained results were assessed (average, error, variance). Results. The results demonstrated that methanol and propanol-2 contents in tinctures did not exceed the limit value, which is set to 0.05 %. However, it was showed that classic gas chromatography is not able to give information about amounts of propanol-2 in substances, while head-space chromatography has determined concentration of this compound in all examined tinctures. It was determined that head-space GC has higher signal-to-noise levels. Conclusions. Considering all shown results and their discussion, it was concluded that method of head – space GC is more sensitive for determination of volatile impurities in liquid medicinal products than classic gas chromatography with common injection technique