P-tert-butyl thiacalix[4]arenes functionalized with amide and hydrazide groups at the lower rim in cone, partial cone, and 1,3-alternate conformations are "smart" building blocks for constructing nanosized structures with metal cations of s-, p-, and d-elements in the organic phase

The ability of p-tert-butyl thiacalix[4]arenes functionalized with tertiary and secondary amide and hydrazide groups at the lower rim in cone, partial cone, and 1,3-alternate conformations to self-assemble and recognize metal ions of s- (Li+,Na+,K+,Cs+), p- (Al 3+, Pb2+)and d- (Fe3+, Co3+, Ni 2+, Cu2+, Ag+, Cd2+, Hg 2+) elements was investigated by picrate extraction method and dynamic light scattering (DLS). DLS was used for determination of the hydrodynamic diameter, polydispersity index, and molecular weight of nanoscale aggregate systems consisting of p-tert-butyl thiacalix[4]arene molecules and metal nitrates. Also for quantitative determination of the dimer shape from the values of molecular weight and the particles size, the Perrin factor (F) was established. It was shown that in most cases the dimers of stereoisomers of p-tert-butyl thiacalix[4]arenes tetra- substituted at the lower rim by secondary amide groups represent the prolate spheroid. © 2009 American Chemical Society

Assessment of the Use of the Potential of Agricultural Lands in Voronezh Region

The uniqueness and specifics of the land significantly affects both the organization of agricultural production and the rural area management. In order to make well-founded management decisions the economic subjects and public authorities need scientific grounding for assessment of land potential and its use efficiency. The authors suggest using three approaches to land quality and use assessment: agro-climatic potential, land quality score and agricultural production per hectare. Uniting these approaches into single assessment procedure produces a fairly objectively estimation of the economic potential of agricultural land in each selected territory

Distance Learning as a Challenge of Time

Статья посвящена актуальной на сегодняшний день проблеме: организация дистанционного обучения в учебном заведении. В статье излагается опыт использования электронного образовательного ресурса MOODLE.The article is devoted to the current problem: the organization of distance learning in an educational institution. The article describes the experience of using the electronic educational resource MOODLE

Self-assembly of nanosized aggregates based on the photoswitchable p-tert-butyl thiacalix[4]arene derivative and Fe III, Cu II, and AgI cations

New p-tert-butyl thiacalix[4]arene tetrasubstituted at the lower rim and containing the azobenzene fragments in the 1,3-alternate configuration was synthesized. Its receptor properties with respect to d-metal cations (Fe 3+, Cu2+, Ag+) were studied using UV spectroscopy and dynamic light scattering (DLS). The ability of p-tert-butyl thiacalix[4]arene to molecular recognition of silver cations was estimated by UV spectroscopy. The aggregation of these systems was studied by the dynamic light scattering method. © 2009 Springer Science+Business Media, Inc

Supramolecular architecture-controlled self-assemblies of calixarenes

The controlled self-assembly of macrocyclic molecules based on calixarenes in functional supramolecular entities is an interesting topic of research in the area of supramolecular chemistry and nanotechnology. Due to many possible applications, such molecule receptors can be useful as base elements in the development of sensors and as selective carriers in industrial membrane extraction technologies. Being highly affine and convertible effectors and catalysts, the calixarenes can be considered as building blocks for constructing nanosized structures adapted for recognition specific guest molecules. The role of calixarenes in the design, synthesis and application of nanoscale aggregates with metal cations by self-association processes is discussed. Among others, the approaches to the synthesis and modification of nanoparticles ranging from 1 nm to 1 mm are considered with particular emphasis to the areas of their possible application in nanotechnology. The discussion is focused on the establishment of the "structure-property" relationships that allow determining size, shape, and chemical properties of the nanoscale aggregates at the spatial structure level as well as their application. The aggregation of metal cations and calixarenes is of special interest due to the following reasons: (i) metal cations can participate in photon absorption or emission, electron transfer, and ion exchange and (ii) synthetic receptors are able to form molecular or supramolecular architectures of predicted spatial arrangement of the active parts, among them, due to their interaction with metal cations. This combination of above mentioned properties is favorable for the synthesis of supramolecular structures with useful chemical, physical and biological properties dependent on the size of components, i.e., the quantity of atoms or molecules forming nanoscale structures. © 2011 by Nova Science Publishers, Inc. All rights reserved

Synthesis of silver and lithium sub-micro-and nanoparticles coated with derivatives of p-tert-butyl thiacalix[4]arenes

The effect of solvent nature and temperature on the formation of 3D-dimensional SAM (selfassembled monolayers on nanoparticles) based on synthetically available stereoisomers of p-tert-butyl thiacalix[4]arenes tetrasubstituted at the lower rim by pyrrolidide and octylamide groups (cone, partial cone, and 1,3-alternate) with lithium and silver nanoparticles were determined by dynamic light-scattering and transmission electron microscopy. It was found that the variation of the temperature of the system and the nature of the solvent leads to the formation discrete or extended particles (CH 2Cl 2) (98-110 nm), nanostructures (CH 3CN) (120-295 nm) or three-dimensional SAM (DMF) (1-13 nm; 46-622 nm). © 2011 Springer Science+Business Media B.V

Cascade and commutative self-assembles of nanoscale three-component systems controlled by the conformation of thiacalix[4]arene

In this work, the formation of two- and three-component supramolecular systems based on cone, partial cone, 1,3-alternate stereoisomers of heteroditopic "hosts": p-tert-butylthiacalix[4]arene containing 4-amidopyridine fragments with silver(I) cations and dicarboxylic acids in liquid and solid phases were studied by UV spectroscopy, dynamic light scattering, and atomic force microscopy methods. It has been shown that these macrocycles are coreceptors, capable of simultaneously binding silver(I) cations, dicarboxylic acids (oxalic, malonic, succinic, maleic, fumaric acids), and hydroxyl acids (glycol, tartaric acids). For the first time, by the dynamic light scattering method, it has been shown that the conformation of p-tert-butyl thiacalix[4]arenes significantly affects the type of three-component system formed: cone is characterized by the formation of cascade systems; for partial cone, intermediate systems; and for the 1,3-alternate stereoisomers, three types of three-component systems (cascade, intermediate, and commutative) were observed. © 2011 American Chemical Society

The synthesis of p-tert-butyl thiacalix[4]arenes functionalized with secondary amide groups at the lower rim and their extraction properties and self-assembly into nanoscale aggregates

In this work, the synthesis of novel p-tert-butyl thiacalix[4]arenes functionalized with the secondary amide groups at the lower rim in cone, partial cone, and 1,3-alternate conformations is described. The ability of novel thiacalixarene derivatives to form dimeric associates held together by hydrogen bonds of p-tert-butyl thiacalixarenes and to recognize metal ions of s (Li+, Na+, K+, Cs+, Mg2+, Ca2+, Ba2+), p (Al3+, Pb2+), and d (Fe3+, Co3+, Ni2+, Cu2+, Ag+, Cd2+, Hg2+) elements was investigated by the picrate extraction method and dynamic light scattering (DLS). As was established, the thiacalix[4]arenes investigated are poor extractants for all the metal ions. Meanwhile they self-associate to form dimers of similar size (1.1-2.7 nm) and nanoscale particles consisting of p-tert-butyl thiacalix[4]arenes and silver cations with hydrodynamic diameters of 70-170 nm. © 2008 Elsevier Ltd. All rights reserved

Non3 is an essential Drosophila gene required for proper nucleolus assembly

The nucleolus is a dynamic non-membrane-bound nuclear organelle, which plays key roles not only in ribosome biogenesis but also in many other cellular processes. Consistent with its multiple functions, the nucleolus has been implicated in many human diseases, including cancer and degenerative pathologies of the nervous system and heart. Here, we report the characterization of the Drosophila Non3 (Novel nucleolar protein 3) gene, which encodes a protein homologous to the human Brix domain-containing Rpf2 that has been shown to control ribosomal RNA (rRNA) processing. We used imprecise P-element excision to generate four new mutant alleles in the Non3 gene. Complementation and phenotypic analyses showed that these Non3 mutations can be arranged in an allelic series that includes both viable and lethal alleles. The strongest lethal allele (Non3∆600) is a genetically null allele that carries a large deletion of the gene and exhibits early lethality when homozygous. Flies heterozygous for Non3∆600 occasionally exhibit a mild reduction in the bristle size, but develop normally and are fertile. However, heteroallelic combinations of viable Non3 mutations (Non3197, Non3310 and Non3259) display a Minute-like phenotype, consisting in delayed development and short and thin bristles, suggesting that they are defective in ribosome biogenesis. We also demonstrate that the Non3 protein localizes to the nucleolus of larval brain cells and it is required for proper nucleolar localization of Fibrillarin, a protein important for post-translational modification and processing of rRNAs. In summary, we generated a number of genetic and biochemical tools that were exploited for an initial characterization of Non3, and will be instrumental for future functional studies on this gene and its protein product

Humanitarization of Education as a Factor of Success of a Competitive Graduate

В статье рассматривается опыт практической апробации государственной стратегии гуманитаризации образования. На базе конкретного средне профессионального образовательного учреждения.The article discusses the experience of practical testing of the state strategy for the humanization of education. On the basis of a specific secondary vocational educational institution