149 research outputs found
Evaluation of toxic action of fluorides on agricultural plants
Вивчено токсичність фтористого натрію, калію та амонію на горох посівний, кукурудзу, овес та цибулю. Встановлено, що рівень токсичного впливу збільшується зі зростанням концентрації фтору у середовищі вирощування (від 5 до 100 мг F–/л). За зростанням токсичного впливу сільськогосподарські культури розташовуються в наступний ряд: овес, цибуля, кукурудза, горох. Фтористий амоній проявляє меншу токсичність, ніж фтористий калій та натрій. За низьких концентрацій сполук фтору (5 і 10 мг F–/л) лише у вівса відмічено стимулювання росту кореневої системи. Изучено токсичность фтористого натрия, калия и аммония на горох посевной, кукурузу, овес и лук. Установлено, что уровень токсического воздействия увеличивается с ростом концентрации фтора в среде выращивания (от 5 до 100 мг F- / л). По возрастанию токсического воздействия сельскохозяйственные культуры располагаются в следующий ряд: овес, лук, кукуруза горох. Фтористый аммоний проявляет меньшую токсичность, чем фтористый калий и натрий. При низких концентрациях соединений фтора (5 и 10 мг F- / л) только у овса отмечено стимулирования роста корневой системы.The toxicity of potassium fluoride, sodium fluoride and ammonium fluoride for pea, maize, oat and onion was studied. It was found that the level of the toxic influence had grown with increase of fluoride concentration in the media of growth (from 5 to 100 mg of F–/l). By increase of the toxic influence the agricultural crops are disposed in the following row: oat < onion < maize < pea. Ammonium fluoride demonstrates lesser toxicity, than potassium and sodium fluorides. Under low concentrations of fluoride compounds (5 and 10 mg of F–/l) stimulation of roots growth is noted only for the oat
Optimum parameters of deoxynivalenol synthesis by micromycete F. graminearum on grain substrates
Today, fusariotoxins play an increasingly important role in the pathology of farm animals, among which deoxynivalenol plays an important role. Deoxynivalenol (DON) is one of the most common fusariotoxins. It affects the health of animals that consume contaminated feed, and can lead to various metabolic disorders, disrupting the body's homeostasis. One of the main effects of deoxynivalenol is that it stimulates the production of anti-inflammatory cytokines, which in turn causes the acute phase of inflammation in animals. In addition, deoxynivalenol leads to a decrease in appetite and can cause hypophagia in animals, which in turn leads to a decrease in daily gains. The direction of the conducted research is aimed at identifying the optimal substrate for the synthesis of deoxynivalenol and its maximum accumulation by the fungus F. graminearum, and also established the optimal parameters for the synthesis of mycotoxin (cultivation temperature, substrate humidity, cultivation period). Grains of the following crops were used as substrates: wheat, rice, corn, barley, oats, rye, millet, millet, peas, soybeans, sunflower, mustard, rapeseed, buckwheat, and flax. Deoxynivalenol in samples was determined by thin-layer chromatography. The production of deoxynivalenol was studied in the temperature ranges of 4, 17, 24, and 28 °C; humidity of the substrate in the range from 14–90 % and the duration of cultivation from 1 to 4 weeks. The mycotoxin-producing activity of the fungus F. graminearum isolate 195/1 was largely determined by the studied parameters. The maximum amount of deoxynivalenol was produced at a temperature of 24 ºС, a substrate humidity of 50%, and a duration of cultivation of 24 days. Of the tested substrates, rice was the best for deoxynivalenol production. The obtained results serve as a basis for possible prediction of feed contamination with deoxynivalenol and, in general, will allow to optimize measures to combat mycotoxicosis and thus minimize the possible risks of mycotoxin poisoning of people and animals
Growth regulators influence on stability of shoots and ascorbic acid content at cadmium and nickel joint action
It is shown that for a maize the most effective protector of cadmium and nickel influence was zeastimulin, for a pea – agrostimulin.A protective function of emistim C for both cultures was insignificant. It is set that zeastimulin is influential in the increased metals absorption of a root system, however substantially (on 15% for a nickel and twice for a cadmium) reduces their translocation to above-ground part of plants. Previous treatment of pea seed by agristimulin also intensified the accumulation of nickel roots on 60% and did not influence on cadmium absorption and toxicants translocation to tissues of assimilatory organs. The protector role of growth regulators to cadmium and nickel joint influence shows up in the increase of ascorbic acid maintenance in the roots cells of both species to 34%, where as in leaves – at a maize resulted in the lowering of vitamin С amount (on 28%), but at a pea – increase on 20%
Influence of dispersion state of initial AlN powder on the hydrolysis process in air environment
The research results of the hydrolysis processes of aluminum nitride powders received by the SVS method in dependence on humidity of the storage environment, and grain size distribution are presented in this work. Oxidation kinetics was estimated by means of X- ray Diffraction (XRD) and scanning electron microscopy (SEM). The induction period of the hydrolysis process for various powders, its dependence on powder dispersion and thickness of the oxide layer on surface of particles have been defined
Features of the Bioconversion of Pentacyclic Triterpenoid Oleanolic Acid Using Rhodococcus Actinobacteria
The ability of actinobacteria of the genus Rhodococcus to transform oleanolic acid (OA), a plant pentacyclic triterpenoid, was shown for the first time using bioresources of the Regional Specialized Collection of AlkanotrophicMicroorganisms (IEGM; WDCM #768;www.iegmcol.ru). The most promising strains (R.opacus IEGM 488 and R.rhodochrousIEGM 285) were selected, and these catalyzed80% bioconversion of OA (0.5 g/L) in the presence of n-hexadecane (0.1% v/v) for seven days. The process of OA bioconversion was accompanied by a gradual decrease in the culture medium pH. Adaptive responses of bacterial cells to the OA effects included the formation of compact cellular aggregates, a marked change in the surface-to-volume ratio of cells, and a significant increase in the Zeta potential values. The results demonstrated that the process of OA bioconversion was catalyzed by membrane-bound enzyme complexes. Participation of cytochrome P450-dependent monooxygenases in the oxidation of the OA moleculewas confirmedusing specific inhibitors. The obtained data expand our knowledge on the catalytic activity of actinobacteria of the genus Rhodococcus and their possible use as biocatalysts for the bioconversion of complex hydrophobic compounds. The results can also be used inthe searchfor promising OA derivatives to be used in the synthesis of biologically active agents.
Keywords: bioconversion, oleanolic acid, Rhodococcus, biologically active compound
Измерители содержания сухих веществ и концентрации жидких продуктов с диэлектрическими свойствами
Описані нові оптичні вимірювачі вмісту сухих речовин у рідких продуктах і концентрації розчинів з діелектричними властивостями. Запропоновані математичні моделі первинних перетворювачів автоматичних рефрактометрів та діелектрометричних комірок на основі прозорих порожнистих циліндрів.New optical dry matters in liquid products maintenance and concentration of solutions with dielectric properties measuring devices are described. The mathematical primary transformers models of automatic refractometers and dielectrometrical cells on the basis of hollow transparent cylinders are offered.Описаны новые оптические измерители содержания сухих веществ в жидких продуктах и концентрации растворов с диэлектрическими свойствами. Предложены математические модели первичных преобразователей автоматических рефрактометров и диэлектрометрических ячеек на основе полых прозрачных цилиндров
Інгібування росту проростків кукурудзи за спільної дії хрому та нікелю
Mutual toxicity of chromium and nickel sulphates for growth and development of maize plantlets was studied. Its combined action at low concentrations (10–5 M) results to significant suppression of growth of both above-ground and root systems of maize. At the beginning of growth the greater negative effect of the salts mixture at high concentration (10–4 M) was observed for the plantlets’ roots. Then, on the sixth day, the growth of above-ground and root system was inhibited equally. Application of high nickel concentration and low chrome concentration, in contrast to high chromium and low nickel levels, depresses the biomass gain. Meanwhile the length of roots and leaves was affected by both variants of concentrations identically.Исследована токсичность воздействия совместного действия хрома сернокислого и никеля сернокислого на рост и развитие проростков кукурузы. Доказано, что их совместное действие при низкой концентрации (10-5 М) приводит к существенному угнетению роста как надземной, так и корневой системы кукурузы. В начале роста кукурузы больше негативный эффект за действия смеси солей в высокой концентрации (10-4 М) проявлялся для корневой системы проростков, а на шестые сутки рост корневой системы и надземной части подавлялся почти в равной степени. Внесение никеля в высокой концентрации на фоне низкой концентрации хрома в большей степени, чем хрома при высокой концентрации на фоне низкого содержания никеля, подавляет накопление массы сырой вещества проростков, тогда как на длину корней и письмо ков они осуществляли одинаковый эффект.Досліджено токсичність впливу спільної дії хрому сірчанокислого та нікелю сірчанокислого на ріст і розвиток проростків кукурудзи. Доведено, що їх спільна дія за низької концентрацій (10–5 М) призводить до суттєвого пригнічення росту як надземної, так і кореневої системи кукурудзи. На початку росту кукурудзи більший негативний ефект за дії суміші солей у високій концентрації (10–4 М) проявлявся для кореневої системи проростків, а на шосту добу ріст кореневої системи та надземної частини пригнічувався майже в однаковій мірі. Внесення нікелю у високій концентрації на тлі низької концентрації хрому більшою мірою, ніж хрому за високої концентрації на тлі низького вмісту нікелю, пригнічує накопичення маси сирої речовини проростків, тоді як на довжину коренів та лист ків вони здійснювали однаковий ефект
Infrared spectroscopy of Nova Cassiopeiae 1993 (V705 Cas). IV. A closer look at the dust
Nova Cassiopeiae 1993 (V705 Cas) was an archetypical dust-forming nova. It
displayed a deep minimum in the visual light curve, and spectroscopic evidence
for carbon, hydrocarbon and silicate dust. We report the results of fitting the
infrared spectral energy distribution with the DUSTY code, which we use to
determine the properties and geometry of the emitting dust. The emission is
well described as originating in a thin shell whose dust has a carbon:silicate
ratio of ~2:1 by number (1.26:1 by mass) and a relatively flat size
distribution. The 9.7micron and 18micron silicate features are consistent with
freshly-condensed dust and, while the lower limit to the grain size
distribution is not well constrained, the largest grains have dimensions
\~0.06micron; unless the grains in V705 Cas were anomalously small, the sizes
of grains produced in nova eruptions may previously have been overestimated in
novae with optically thick dust shells. Laboratory work by Grishko & Duley may
provide clues to the apparently unique nature of nova UIR features.Comment: 11 pages, 9 fugure
Dynamics of the north western coast of the azov sea
UA: Современная динамика склонов и побережья морей как отображение общего мобилизма литосферы, взаимодействия основных оболочек Земли под влиянием космических, планетарных, региональных и локальных
факторов является актуальной научной и практической проблемой. В цепочке геолого-геоморфологических процессов склоновые гравитационные процессы являются наиболее активным звеном и непосредственно влияют на
жизнедеятельность человека. В свою очередь, хозяйственная деятельность человека вносит существенные изменения в процесс эволюции геологической среды, в том числе в характер протекания склоновых процессов. EN: Development of slope gravity processes on the coast of the Sea of Azov is a serious environmental and geological problem and requires topical engineering and geological research and solutions. Slope gravitational processes adversely affect the state of the soil layer, causing erosion and washing away of soils, contribute to siltation and contamination of water bodies. Movements on the slopes cause destruction of economic objects, residential buildings, loss of agricultural land. To prevent the negative consequences of slope processes, their deep and systematic study is necessary
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