Efficient solar light harvesting device based on multilayer photonic crystal films

We fabricate, characterize and calculate photonic-colloidal crystals. We propose to use wave guiding properties of photonic crystal films [1] to concentrate large amount of sunlight onto a small area of solar photovoltaic (PV) cells

Photosynthetic pigments and phytochemical activity of photosynthetic apparatus of maize (Zea mays L.) leaves under the effect of thiamethoxam

In the last decade, neonicotinoid insecticides have been actively used to protect plants from pests. Moreover, their effect on the plants, in particular on the state of photosynthetic pig-ments, has been studied paucity. In the present work, it was shown for the first time that treatment of maize (Zea maysL.) leaves with a thiamethoxam (TMX) insecticide leads to a decrease in the functional activity of photosystem II and a decrease in the energyzation of thylakoid membranes. In addition, the effect of thiamethoxam depends on the genotype of maize. The aim of the work was to study the effect of thiamethoxam pesticide on photosynthetic pigments and the photochemical activi-ty of the photosynthetic apparatus of maize leaves of two genotypes. The experiments were carried out in 2018-2019.The object of the study was samples of maize leaves of the inbred line zppl 225 and hybrid zp 341 with high rates of germination, grain quality and yield (Institut za kukuruz “Zemun Polje”, Belgrade, Serbia). The seeds were germinated until the roots appeared (length not less than 5mm),after which they were planted in the soil (vermiculite:chernozem mixture, 1:1) and grown under 16-hour daylight at a constant temperature of 25 С. When the third trueleaf appeared (more than 4 cm in length), the plants were sprayed with a TMX solution at a concentration of 0.2 mg/l. Plants grown under similar conditions without TMX spraying were used as controls. The measurements were carried out when the fifth true leaf reached a size of 12-14 cm.The content of photosynthetic pigments (chlorophyll a, b and carotenoids) was determined spectrophotometrically in 100% acetone extract and calculated using the Holm-Wetstein formula. A change in the confor-mation of carotenoid molecules was recorded by Raman spectroscopy.Light-induced kinetics of prompt fluorescence (PF), delayed fluorescence (DF) and modulated reflection at = 820 nm (MR) were recorded simultaneously using a multifunctional plant efficiency analyzer M-PEA-2 (Hansatech Instruments, Great Britain). PF induction curves (OJIP curves) were analyzed using a standard JIP-test. It was found that in the phase of the fifth true leaf, in the inbred line zppl 225, the chlorophyll content in the presence of TMX decreased from 0.74 to 0.61 mg/g: the amount of chlorophyll a decreased by 17 %, chlorophyll b by 24 %. In contrast, no changes in pigment composition were detected in the leaves of the zp 341 hybrid when exposed to TMX. The OJIP curves of the control and TMX-treated leaves had a typical curve with characteristic O-J, J-I, and I-P phases, which re-flected the processes of sequential reduction of carriers in the electron transport chain of photosyn-thesis (ETC) between two photosystems. The effect of the pesticide onthe leaves of two maize geno-types was manifested in a decrease in the functional state of photosystem II, determined by the fluo-rescence parameter (PIABS), which was obtained based on the analysis of OJIP curves using the JIP-test. Comparison of PIABSin the control and under the influence of TMX revealed statistically sig- 67nificant (p < 0.05) differences: in the leaves of zppl 225 and zp 341 samples treated with TMX, the PIABSparameter decreased by 29 and 24%, respectively. Changes in the fast phase of delayed fluo-rescence, associated with a decrease in the energyzation of the thylakoid membrane upon exposure to TMX, were detected in the leaves of maize. An analysis of the maximum oxidation and reduction rates of P700 (MR kinetics) indicates a decrease in the acceptor pool on the acceptor side of PSI in zppl 225 leaves when exposed to TMX. It was found that the reaction centers (RCs) of PSI zp 341 showed resistance to TMX (no change in the redox transformations of P700). TMX caused changes in the conformation of carotenoid molecules, but did not change their content in the leaf. The pro-posed combination of methods for prompt fluorescence, delayed fluorescence, modulated reflection at = 820 nm and Raman spectroscopy can be the basis for the formation of an effective technology for the diagnosis of early defects of photosynthetic pigments when pesticides enter an intact plant

Определение острой токсичности новых гетерометаллических соединений – тартратогерманатов меди и цинка

Одним із можливих шляхів створення нових лікарських препаратів є прицільний синтез сполук із попередньо передбаченою активністю. Перспективним у цьому плані є одержання комплексів на основі іонів металів і лігандів. Мета роботи – встановити токсикометричні характеристики нових біологічно активних речовин – тартратогерманатів. купруму та цинку в гострому експерименті. Матеріали та методи. Вивчали гостру токсичність на мишах і щурах за умов перорального приймання (п/о), підшкірного (п/ш) і внутрішньоочеревинного (в/оч) введення. Критерієм токсичності досліджуваних сполук був показник ЛД50, що визначався з використанням методу пробіт-аналізу. Крім того, обчислена низка інтегральних показників токсичності, зокрема абсолютна токсичність, зона гострої токсичної дії, сумарний показник токсичності тощо. Результати. Згідно з отриманими результатами, показник LD50 купрум-тартратогерманату у мишей становив 36,88 мг/кг (в/о); 63,78 мг/кг (п/ш) і 385,57 мг/кг (п/о); в щурів – 78,16; 135,05 і 794,26 мк/кг відповідно. Індекс LD50 цинк-тартратогерманату у мишей становив 87,20 мг/кг (в/о); 167,05 мг/кг (п/ш) і 1675,40 мг/кг (п/о); у щурів – 141,57; 236,52 і 2792,45 мк/кг відповідно. Нова координаційна сполука цинк-тартратогерманат належить до малотоксичних сполук (IV клас токсичності) за умов внутрішньоочеревинного, підшкірного та перорального введення в обох видів тварин, водночас купрум-тартратогерманат є помірно токсичною речовиною (ІІІ клас токсичності). Цинковмісні сполуки виявили меншу токсичність, аніж аналогічні сполуки з купрумом. Відповідно до отриманих даних варіабельність смертельних доз при різних шляхах введення тартратогерманату купруму становила 1,32–1,60 (у мишей) і 1,66–1,92 (у щурів); тартратогерманату цинку – 1,31–1,50 (у мишей) та 1,24–1,37 (у щурів). Інтегральні показники безпечності нових БАР, що містять цинк, були найбільшими за умов перорального введення, водночас нові сполуки, що містять купрум, були найбезпечнішими за умов ін’єкційного введення. Висновки. Доволі невелика токсичність нових сполук тартратогерманатів цинку та купруму свідчить про перспективність їхнього подальшого доклінічного дослідження як потенційних лікарських засобів.One of the possible ways of creating new drugs is aiming synthesis of compounds previously envisaged activity. Perspective in this area is to obtain complexes based on metal ions and ligands. Purpose: To establish toxikometric characteristics of new biologically active substances – tartratogermanat copper and zinc in the acute experiment. Materials and methods: Studied acute toxicity in mice and rats under the conditions of oral (o), subcutaneous (s/c) and intraperitoneal (i/p) administration. The toxicity criterion of the test compounds was LD50, which was determined using the probit analysis method. In addition, a number of integrated toxicity indicators were calculated, in particular absolute toxicity, an acute toxic effect zone, a summary toxicity index and etc. The results: According to the results, the LD50 index of copper-tartratogermanate in mice was 36.88 mg/kg (i/p) 63.78 mg/kg (s/c) and 385.57 mg/kg (o); in rats – 78.16; 135.05 and 794.26 m/kg, accordingly. The LD50 index of zinc-tartratogermanate in mice was 87.20 mg/kg (i/p) 167.05 mg/kg (s/c) and 1675.40 mg/kg (o); in rats – 141.57; 236.52 and 2792.45 μ/kg, accordingly. The new compound of zinc tartratogermanat belongs to low-toxic compounds (IV class of toxicity) in conditions of intraperitoneal, subcutaneous and oral administration in two animal species, in the same time-tartratogermanat copper is moderately toxic (toxicity class III). Zinc-containing compounds showed lower toxicity than similar compounds with cuprum. According to the resalts, the variability of the lethal doses for various routes of administration of copper tartrate-hommanate was 1.32–1.60 (in mice) and 1.66–1.92 (in rats) zinc tartrate-germanate, 1.31–1.50 (in mice) and 1.24–1.37 (in rats). Integral safety of the new BAС showes that compounds with zinc were more safety in oral take, while new compounds containing copper were the safest under conditions of injection. Conclusions: A small toxicity of new compounds tartratogermanat zinc and copper indicates the prospects for their further preclinical studies as potential drugs.Одним из возможных путей создания новых лекарственных препаратов является прицельный синтез соединений с предварительно предусмотренной активностью. Перспективно в этом плане получение комплексов на основе ионов металлов и лигандов. Цель работы – установить токсикометрические характеристики новых биологически активных веществ – тартратогерманатов меди и цинка – в остром эксперименте. Материалы и методы. Изучали острую токсичность на мышах и крысах в условиях перорального приема (п/о), подкожного (п/к) и внутрибрюшинного (в/б) введения. Критерием токсичности исследуемых соединений был показатель ЛД50, который определялся с использованием метода пробит-анализа. Кроме того, вычислен ряд интегральных показателей токсичности, в частности абсолютная токсичность, зона острого токсического действия, суммарный показатель токсичности и тому подобное. Результаты. Согласно полученным результатам, показатель LD50 меди-тартратогерманата у мышей составил 36,88 мг/кг (в/б); 63,78 мг/кг (п/к) и 385,57 мг/кг (п/о); у крыс – 78,16; 135,05 и 794,26 мк/кг соответственно. Индекс LD50 цинк-тартратогерманата у мышей составил 87,20 мг/кг (в/б); 167,05 мг/кг (п/к) и 1675,40 мг/кг (п/о); у крыс – 141,57; 236,52 и 2792,45 мк/кг соответственно. Новое координационное соединение цинк-тартратогерманат относится к малотоксичным соединениям (IV класс токсичности) в условиях внутрибрюшинного, подкожного и перорального введения у двух видов животных, в то же время купрум-тартратогерманат – умеренно токсичное вещество (ІІІ класс токсичности). Цинк-содержащие соединения проявили меньшую токсичность, чем аналогичные соединения с купрумом. Согласно полученным данным, вариабельность смертельных доз при различных путях введения тартратогерманата купрума составляла 1,32–1,60 (у мышей) и 1,66–1,92 (у крыс); тартратогерманата цинка – 1,31–1,50 (у мышей) и 1,24–1,37 (у крыс). Интегральные показатели безопасности новых БАВ, содержащих цинк, были наибольшими при пероральном приеме, в то же время новые соединения, содержащие купрум, были наиболее безопасными в условиях инъекционного введения. Выводы. Достаточно небольшая токсичность новых соединений тартратогерманатов цинка и купрума свидетельствует о перспективности их дальнейшего доклинического исследования в качестве потенциальных лекарственных средств

COORDINATION COMPOUNDS Sn (IV) WITH HYDROXYCARBOXYLIC ACIDS

This article presents a review of the literature, related to complex compounds of tin (IV) with hydroxycarboxylic acids. Results of investigations of complexing ability of a Lewis acid – tin tetrachloride (IV) in combination with the s-, d-metals ions relative to hydroxycarboxylic acids, obtained in recent years at the Department of General chemistry and polymers ONU I. I. Mechnikov

SYNTHESIS AND STRUCTURE OF COMPLEXES BY CO(II) AND NI(II) WITH PYRIDINOYLHYDRAZONES OF PYRUVIC ACID

The interaction of MX2 (M = Co2+, Ni2+; X = Cl-, CH3COO-, NO3-) with nicotinoyl- and isonicotinoyhydrazones of pyruvic acid (H2Npv, H2Ipv) in metanol has been studied. Methods are developed and 8 new complexes are first synthesized: — with Co2+, Ni2+ chlorides: [NiCl(HNpv)(H2O)2] (I), [NiCl(HIpv)(H2O)2] (II), [CoCl(HNpv) (H2O)2] (III), [CoCl(HIpv)(H2O)2] (IV); — with Co2+, Ni2+ acetates and nitrates: [Ni(HNpv)2]2CH3OH (V), [Ni(HIpv)2]2CH3OH (VI), [Co(HNpv)2]CH3OH (VII), [Co(HIpv)2]CH3OH (VIII). Complexes have been characterized by a set of methods element analysis, thermogravimetry, IR and diffuse reflection spectroscopy, mag­netic susceptibilites measurings. The scheme of their structure has been proposed. It was established that in all complexes was implemented the same monodeproto- natid ketone form HLpv- with coordination through the azometine nitrogen atom and carbonilic and carboxylic groups oxygens, without the participation of the pyridine nitrogen

SYNTHESIS, STRUCTURE AND THERMAL PROPERTIES OF GERMANIUM(IV), TIN(IV) COMPLEXES WITH RS-MANDELIC ACID

Germanium(IV) and tin(IV) coordination compounds [Ge(Mand)2(H2O)2]∙2H2O (1), (H3O) [Ge(OH)(Mand)2] (2), [Sn(Mand)(HMand)2] 5Н2О (3) were synthesized for the first time with the RS-mandelic acid. Thermogravimetric analysis of 1-3 shows, that compounds are crystalohydrates. Thermal destruction of 1 and 2 is gradational. In the thermal interval 80-160°С an endothermic effect with the maximum at 140°С and weight loss, which corresponds to two molecules of crystalline water, is observed. At 160-220°С two more water molecules are deleted from the inner sphere of the complex. On the thermogram of 2 in the thermal interval 140-240°С the first endoeffect with the weight loss of two water molecules, that are bonded more fixedly, then crystalline ones, is observed. In contrast with 1 and 2, during the heating of 3 in the thermal interval of 80-170°С, an endothermic effect, which is followed by elimination of 5 crystalline water molecules, is observed. Disappearing of ν(С=О) = 1716 сm-1 absorption band and presence of νas(СОО–) = 1690 сm-1 in 1 (pic. 2.4 б), νas(СОО–) = 1688 сm-1, νs(СОО–) = 1323 сm-1 in 2 and νas(СОО–) = 1654 сm-1, νs(СОО–) =1322 сm-1 in 3 shows the presence of bonding between carboxyl group and germanium (tin) in 1-3. The bonding between hydroxyl group and metals is confirmed by presence of ν(С-О) absorption band at 1064 сm-1. Herewith in the spectra of complexes 1 and 2 deformation vibrations С-ОН are absent, and in spectrum of 3 they are presented at 1494 сm-1. The bonding is also confirmed by presence of valence vibrations bands of the Ge-O bond equal 744 сm-1 in 1 and 737 сm-1 in 2, and in the spectrum of 3 by presence of ν(Sn-О) = 567 сm-1. In the spectrum of 2 the clear absorption band at 834 сm-1, which corresponds to the deformation vibrations of Ge-O-H-group, is found. Consequently, germanium is presented in the compound in the hydrolyzed form. The schemes of structures are presented

COMPARATIVE CHARACTERISTICS OF Co(II), Ni (II), Cu(II) COORDINATION COMPOUNDS WITH SOME HYDRAZONES OF PYRUVIC ACID

Сonducted comparative analysis of the coordination compounds of Co2+, Ni2+, Cu2+ with condensation products of 2-(7-bromo-2-oxo-5-phenyl-2,3-dihydro-1H-1,4-benzodiazepin-1-yl) acetohydrazide – Hydazepam (Hydr), nicotinoyl- and isonicotinoyl hydrazones (H2N, H2I) with pyruvic acid (HPv): [Co(HydrHPv)Cl2]·2H2O (I), [Ni(HydrPv)2] (II), [Cu(HydrHPv) (H2O)Cl2] (III), [CoCl(HNPv)(H2O)2] (IV), [CoCl(HIPv)(H2O)2] (V), [NiCl(HNPv)(H2O)2] (VI), [NiCl(HIPv)(H2O)2] (VII), [CuCl(HNPv)]·H2O (VIII), [CuCl(HIPv)]·H2O (IX). Complexes characterized by elemental analysis, IR spectroscopy, electrical conductivity, and magnetic susceptibility. Thermal stability of the complexes has been characterized. Structure of the coordination node of the complexes has been determined by EXAFS-spectroscopy. Regardless of composition, structure by heterocyclic nitrogen-containing moiety of the molecules HydrHPv, H2NРv, H2IРv formation of I-IX complexes is due to binding of complexing with a hydrazide functional group ketone form of the ligands. Ni2+ complexes II, VI, VII are different by composition (Ni2+:HydrHPv в II = 1:2, Ni2+:H2NРv(H2IРv) в VI, VII = 1:1). Co2+, Cu2+ complexes with the same composition (M2+:ligand = 1:1). H2NPv, H2IPv in all complexes IV-IX – tridentate, occurs deprotonation and bonding carboxylate group НPv. HydrHPv coordinated to the Co2+, Cu2+ bidentate (I, III), without participation of the carboxylic group, and to the Ni2+ – tridentate (II)

FEATURES OF INITIATION OF STYRENE POLYMERIZATION BY CUMENE HYDROPEROXIDE IN PRESENCE OF ACETULACETONATE OF COPPER(II)

Kinetics of sectional styrene polymerization initiated by cumene hydroperoxide, acetylacetonate of copper(II) and by the system of cumene hydroperoxide — acetylacetonate of copper(II) in a temperature range 333-363 K is studied. Kinetic parameters of polymerization process are determined. It is shown, that system of cumene hydroperoxide — acetylacetonate of copper(II) is in 5-6 times more effective on the initiating ability comparatively to application of its individual components. From findings ensues that decline of energy of activating of initiation from 110 kdzh/mol’ to 87 kdzh/mol’ for cumene hydroperoxide at the use of the studied system is caused with participating of monomer in preliminary complexation facilitating formation of free radicals