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Computer models of tape and coil inductors are described, and a comparison of the heating efficiency depending on various parameters is made. The developed computer model was made in the ELCUT 6.0. As a result of the simulation, data on the heating characteristics (depending on the various parameters of the heating elements) are obtained. The average statistical data of a series of experiments with a tape inductor are given. It is shown that for the same parameters (values of inductance and number of wires), the tape version inductor heats up a pipe to a higher temperature (by 5.08%) than the inductor in the coil version in 10 minutes.

The phase composition and magnetic properties of FeNi nanoparticles encapsulated in carbon with a nickel content of about 10% are studied in comparison with FeNi nanoparticles of similar composition without carbon coating. The Fe91Ni9 particles have the body centered cubic structure, whereas the Fe88Ni12@C particles have the face centered cubic (FCC) structure. The Fe88Ni12@C particles are characterized with a rather high magnetization of 60 emu g−1 in the field of 30 kOe at 5 K and 40 emu g−1 at 300 K. The monotonous behavior of magnetization with temperature gives grounds to assume that the Fe88Ni12@C particles retain the FCC structure over the entire temperature range down to 5 K. It is concluded that the stabilization of FCC phase of Fe88Ni12@C and the ferromagnetic state of this FCC phase are related to a large concentration of carbon in the core of the nanoparticles. [ABSTRACT FROM AUTHOR]

Heterochromatin is a specialized chromatin structure in chromosomal regions associated with repeated DNA sequences and low concentrations of genes. Formation of heterochromatin is determined in large part by enzymes that modify histones and structural proteins that bind to these modified histones in a cooperative fashion. In Drosophila, mutations in genes that encode heterochromatic proteins are often dominant and increase expression of genes placed into heterochromatic positions. To find components of telomeric heterochromatin in Drosophila, we screened a collection of autosomal deficiencies for dominant suppressors of silencing of a transgene at the telomere of chromosome 2L. While many deficiency chromosomes are associated with dominant suppressors, in the cases tested on chromosome 2 the suppressor mapped to the 2L telomere, rather than the deficiency. We infer that background effects may hamper the search for genes that play a role in telomeric heterochromatin formation and that either very few genes participate in this pathway or mutations in these genes are not dominant suppressors of telomeric position effect. The data also suggest that the 2L telomere region plays a major role in telomeric silencing.

Heterochromatin is a major component of higher eukatyotic genomes, but progress in understanding the molecular structure and composition of heterochromatin has lagged behind the production of relatively complete euchromatic genome sequences. The introduction of single-copy molecular-genetic entry points can greatly facilitate structure and sequence analysis of heterochromatic regions that are rich in repeated DNA. In this study, we report the isolation of 502 new P-element insertions into Drosophila melanogaster centric heterochromatin, generated in nine different genetic screens that relied on mosaic silencing (position-effect variegation, or PEV) of the yellow gene present in the transposon. The highest frequencies of recovery of variegating insertions were observed when centric insertions were used as the source tot mobilization. We propose that the increased recovery of variegating insertions from heterochromatic starting sites may result from the physical proximity of different heterochromatic regions in germline nuclei or from the association of mobilizing elements with heterochromatin proteins. High frequencies of variegating insertions were also recovered when a potent suppressor of PEV (an extra Y chromosome) was present in both the mobilization and selection generations, presumably due to the effects of chromatin structure on P-element mobilization, insertion, and phenotypic selection. Finally, fewer variegating insertions were recovered after mobilization in females, in comparison to males, which may reflect differences in heterochromatin structure in the female and male germlines. FISH localization of a subset of the insertions confirmed that 98% of the variegating lines contain heterochromatic insertions and that these schemes produce a broader distribution of insertion sites. The results of these schemes have identified the most efficient methods for generating centric heterochromatic P insertions. In addition, the large collection of insertions produced by these screens provides molecular-genetic entry points for mapping, sequencing, and functional analysis of Drosophila heterochromatin.

One model of telomeric position effect (TPE) in Drosophila melanogaster proposes that reporter genes in the vicinity of telomeres are repressed by subterminal telomere-associated sequences (TAS) and that variegation of these genes is the result of competition between the repressive effects of TAS and the stimulating effects of promoters in the terminal HeT-A transposon array. The data presented here support this model, but also suggest that TPE is more complex. Activity of a telomeric white reporter gene increases in response to deletion of some or all of the TAS on the homolog. Only transgenes next to fairly long HeT-A arrays respond to this trans-interaction. HeT-A arrays of 6-18 kb respond by increasing the number of dark spots on the eye, while longer arrays increase the background eye color or increase the number of spots sufficiently to cause them to merge. Thus, expression of a subtelomeric reporter gene is influenced by the telomere structure in cis and trans. We propose that the forces involved in telomere length regulation in Drosophila are the underlying forces that manifest themselves as TPE. In the wild-type telomere TAS may play an important role in controlling telomere elongation by repressing HeT-A promoter activity. Modulation of this repression by the homolog may thus regulate telomere elongation.

Approximately one-third of the human and Drosophila melanogaster genomes are heterochromatic, yet we know very little about the structure and function of this enigmatic component of eukaryotic genomes. To facilitate molecular and cytological analysis of heterochromatin we introduced a [yellow.sup.+] ([y.sup.+])-marked P element into centric heterochromatin by screening for variegated phenotypes, that is, mosaic gene inactivation. We recovered > 110 P insertions with variegated yellow expression from ~3500 total mobilization events. FISH analysis of 71 of these insertions showed that 69 (97%) were in the centric heterochromatin, rather than telomeres or euchromatin. High-resolution banding analysis showed a wide but nonuniform distribution of insertions within centric heterochromatin; variegated insertions were predominantly recovered near regions of satellite DNA. We successfully used inverse PCR to clone and sequence the flanking DNA for ~63% of the insertions. BLAST analysis of the flanks demonstrated that either most of the variegated insertions could not be placed on the genomic scaffold, and thus may be inserted within novel DNA sequence, or that the flanking DNA hit multiple sites on the scaffold, due to insertions within different transposons. Taken together these data suggest that screening for yellow variegation is a very efficient method for recovering centric insertions and that a large-scale screen for variegated yellow P insertions will provide important tools for detailed analysis of centric heterochromatin structure and function.

Cycloaddition of dibenzoxazepinium ylides to acetylene carboxylates has led to cis-3-aryl-3,13b-dihydrodibenzo[b,f]pyrrolo[1,2-d][1,4]oxazepinecarboxylates, which has dehydrogenated to the corresponding pyrrole derivatives. Stereoselective cycloaddition of dibenzoxazepinium ylides to fullerene [C.sub.60] has given rise to fulleropyrrolidines with cis-configuration and restricted Ph group rotation is seen in the phenyl derivative.

In the experiment the biological activity of copper and zinc alloy nanoparticles prepared by gas phase synthesis in an argon atmosphere was assessed. Nanoparticle preparations differed in phase composition and specific surface for CuZnNPs1 - 36 m²/g, CuZnNPs2 - 22 and CuZnNPs3 NP - 15 m²/g. As the test cultures, E.coli K12 TG1 pF1, E.coli K12 MG1655 katG::lux, E.coli MG1655 pRecA-lux, E.coli K12 MG1655 psoxS::lux were used. As the results showed, phase composition and specific surface area of nanoparticles were their toxicity factors. CuZnNPs3 is the most toxic among the studied samples the percentage of zinc phase in it in comparison with other tested powders, is the largest (52.3%), and the percentage of metallic copper is the smallest (7.9%). Within further works is to carry out controlled synthesis that will allow changing the toxicity of the nanoparticles under study by phase composition and specific surface. [ABSTRACT FROM AUTHOR]

Malignant transformation is associated with loss of cell differentiation, anaplasia. Transcription factors gli, required for embryonic development, may be involved in this process. We studied the activity of transcription factors gli in high-grade gliomas and their role in maintenance of stem cell state and glioma cell survival. 20 glioma cell lines and a sample of a normal adult brain tissue were used in the present study. We found the expression of gli target genes, including GLI1 and FOXM1, in all tested glioma cell lines, but not in the normal tissue. Interestingly, the expression of gli target genes in some glioma cell lines was observed together with a high level of their transcriptional repressor, Gli3R. Knockdown of GLI3 in one of these lines resulted in decrease of gli target gene expression. These data suggest that Gli3R does not prevent the gli target genes transcription, and gli3 acts in glioma cells more as an activator, than a repressor of transcription. We observed that gli regulated the expression of such genes, as SOX2 or OCT4 that maintain stem cell state, and TET1, involving in DNA demethylation. Treatment with GANT61 or siRNA against GLI1, GLI2, or GLI3 could result in complete glioma cell death, while cyclopamine had a weaker and line-specific effect on glioma cell survival. Thus, the gli transcription factors are abnormally active in high-grade gliomas, regulate expression of genes, maintaining the stem cell state, and contribute to glioma cell survival. [ABSTRACT FROM AUTHOR]

Genetically marked P elements inserted into the subtelomeric satellites of Drosophila show repression and variegation of the reporter gene. One such [white.sup.+] reporter, inserted between the subtelomeric satellite and the terminal HeT-A array in the left arm of chromosome 2 (2L), is sensitive to its context; changes in the structure of the telomere region can be identified by changes in eye color. Addition of HeT-A or TART elements to the 2L terminus increases [w.sup.+] expression, and loss of sequence from the end decreases expression. This indicates that the telomeric retrotransposons in Drosophila have an activating influence on the repressed subterminal reporter gene. Changes in eye color due to altered expression of the transgene also allow the detection of interactions between homologous telomeres. The 2L arms that terminate in long HeT-A/TART arrays showed increased expression of the subterminal [w.sup.+] transgene when the terminal repeats on the homologue are absent or markedly shorter. We propose that the chromatin structure of the terminal HeT-A/TART array and the activity of a putative promoter/enhancer element on HeT-A are affected by telomeric interactions. Such trans-activation may reflect control over HeT-A transcription and, thus, transposition activity.

Electroactive and conductive polymers based on transition metal complexes with salen‐type ligands are of interest as potential materials for energy storage and solar energy conversion. The easily tunable structure of monomers allows to modify polymer properties by changing either the central metal atom or the ligand substituents. Herein we report the photoelectrocatalytic activity of [MII(L)]n complexes, where M is Ni, Cu or Pd, and L is a tetradentate N,N,O,O salen‐type ligand, in the reduction of molecular oxygen to hydrogen peroxide in water solutions on polymer‐coated ITO electrodes. The photocathodic current at 0 V vs. Ag/AgCl is pH‐dependent, reaching maximum at pH 1 and dropping almost to zero at pH 12. Hydrogen peroxide production is almost quantitative (97 % efficiency measured in 1‐compartment cell). Maximal photocurrent and H2O2 concentrations achieved comprise 23 μA/cm2 and 1.3×10−3 M respectively. Energy conversion: Ni‐salen complexes are synthesised and characterised as electrocatalysts for solar energy conversion. In experiments for solar energy conversion, it is shown that the catalysts can be applied for generating a photocurrent or for the production of hydrogen peroxide as a chemical fuel. [ABSTRACT FROM AUTHOR]

The nickel salen-type redox polymers represent an interesting class of organometallic polymers frequently used in hybrid supercapacitor electrodes as thin films and carbon material composites. However, the suitability of these compounds for application as electrode materials for rechargeable batteries has not yet been tested. In this study, redox processes in monocomponent electrodes based on a series of nickel salen-type redox polymers are investigated in 1 m LiPF6 in 1:1 ethylene carbonate (EC)/diethyl carbonate (DEC) electrolyte in a Li-ion battery. The oxidation potentials for polymer complexes of nickel exceed 3.5 V versus Li/Li+, which enhances specific energy. It is found that introduction of a proper substituent in the phenyl ring of the ligand allows to fabricate additive-free electrodes which demonstrate high charge/discharge rate performance with the capacity on discharge at 10 C being up to 73% of the capacity obtained at discharge at 1 C, which corresponds to maximum power of 2.6 kW kg−1. [ABSTRACT FROM AUTHOR]

A novel electrode material was prepared by electrochemical oxidation of [4,4′-phenylazo-2,2′-(ethylenediimino-κ2N-methyl)diphenolate-κ2O]nickel, a [Ni(ii)(salen)]-type complex, in chlorinated solvent. The chemical structure of the material was explored by FTIR, NMR and XPS techniques to determine the main components of the material and the nature of the linkage between them. The morphology of the material films was explored by SEM analysis. The electrochemical properties of the new material were studied by a set of voltammetric methods and an unusual stability of the material in aqueous medium was observed. [ABSTRACT FROM AUTHOR]

Specially designed porphyrin-fullerene dyads have been synthesized to verify literature predictions based on quantum chemistry calculations that certain porphyrin-fullerene dyads are able to self-arrange into specific structures providing channels for charge transport in a bulk mass of organic compound. According to AFM and SEM data, the newly synthesized compounds were indeed prone to some kind of self-arrangement, although to a lesser degree than was expected. A dispersion corrected DFT study of the molecular non-covalent interactions performed at the DFT-D3 (B3LYP, 6-31G*) level of theory showed that the least energy corresponded to head-to-head dimers, with close contacts of porphyrin-porphyrin and fullerene-fullerene fragments, thus providing a unit building block of the channel for charge transport. Experimental proof for the existence of channels for charge transport was obtained by observing a photocurrent in a simple photovoltaic cell. [ABSTRACT FROM AUTHOR]

A series of covalently linked axially symmetric porphyrin-fullerene dyads with a rigid pyrrolo[3,4- c]pyrrolic linker enabling a fixed and orthogonal arrangement of the chromophores has been synthesized and studied by means of transient absorption spectroscopy and cyclic voltammetry. The lifetime of the charge-separated state has been found to depend on the substituents on the porphyrin core, reaching up to 4 μs for a species with meso-( p-MeOC6H4) substituents. The ground and excited electronic states of model compounds have been calculated at the DFT and TD-DFT B3LYP(6-31G(d)) levels of theory and analyzed with regard to the effect of the substituent on the stabilization of the charge-separated state in the porphyrin-fullerene ensemble with a view to explaining the observed dependence. [ABSTRACT FROM AUTHOR]

The quantum-chemical calculations of the thermal ring opening of 1-methyl-2,3-diphenyl- and 1,2,3-triphenylaziridine with formation of the corresponding azomethine ylides of S-, U-, and W-type as well as their cycloaddition to dimethyl acetylenedicarboxylate (DMAD) and dimethyl 2,3-dicyanobut-2-enedioate, were performed at the DFT B3LYP/6-31G(d) level of theory with the PCM solvation model. The calculations are in complete accordance with experimental results and explain the switch from the concerted to the non-concerted pathway depending on substituents in the dipolarophile and the ylide. It was found that strong electron-withdrawing substituents in dipolarophiles, such as in dialkyl dicyanobutenedioates, significantly reduce the barrier for the formation of zwitterionic intermediates in the reaction of azomethine ylides with such dipoles. This can render the stepwise cycloaddition competitive with the concerted one. However, the concertedness of the cycloaddition even to dipolarophiles with several electron-withdrawing substituents is governed by a fine balance of electronic and steric effects in both ylide and dipolarophile counterparts. The hypothesis that introduction of substituents in the azomethine ylide that destabilize the positive charge in a corresponding zwitterion will favor the concerted cycloaddition even with dialkyl dicyanobutenedioates was tested theoretically and experimentally. [ABSTRACT FROM AUTHOR]

The polycycloaddition of azomethine ylides to dipolarophiles is described for the first time. Use of ( cis, cis)-bis-aziridines as a source of azomethine ylides allows selective polyaddition to be realized, which leads to oligomers exclusively with trans-substituted pyrrolidine rings and modest molecular weights (ca. 5-10 kDa). The fluorescent, electrochemical, electrochromic, and non-linear optical properties of the main-chain free-base porphyrin oligomer, synthesized by the developed procedure, are studied. An enhancement of the optical power limiting effect in a porphyrin oligomer solution is registered against that of the monomer. [ABSTRACT FROM AUTHOR]

A new approach to porphyrinofullerene donor-acceptor dyads, based on consecutive 1,3-dipolar cycloaddition of azomethine ylides, generated from bis-aziridinedicarboxylate, to C60 and to porphyrin with a maleimidophenyl substituent, was developed. A synthesis of the axially symmetric porphyrin-fullerene-C60 ensemble 5 with a novel rigid pyrrolo[3,4-c]pyrrolic linker was realized. Theoretical, electrochemical, and spectroscopic studies of compound 5 showed that it is capable of forming a charge-separated state. [ABSTRACT FROM AUTHOR]

The synthesis of alkoxycarbonyl-substituted bisa-ziridines with the two aziridine units connected by conjugated p-phenylene, partly conjugated 1,1'-biphenyl-4,4'diyl, and non-conjugated 4,4'-metriylenediphenyI linkers was developed. The reaction of azomethine ylides derived from the bisaziridines with fullerene C60 was optimized and used for the stereoselective preparation of both the monoadducts (C60-linker-aziridine dicarboxylate), and the dumbbell bisadducts (C60-linker-C60). The reasons for the observed selectivity of the azomethine ylide formation and cydoaddition were theoretically studied at the DFT B3LYP/6-31G(d) level or at the ON1OM B3LYP/631G(d):B3LYP/STO-3G level for fullerene-containing molecules. [ABSTRACT FROM AUTHOR]

ATRX belongs to the family of SW12/SNF2-like ATP-dependent nucleosome remodeling molecular motor proteins. Mutations of the human ATRX gene result in a severe genetic disorder termed X-linked α-thalassemia mental retardation (ATR-X) syndrome. Here we perform biochemical and genetic analyses of the Drosophila melanogaster ortholog of ATRX. The loss of function allele of the Drosophila ATRX/XNP gene is semilethal. Drosophila ATRX is expressed throughout development in two isoforms, p185 and p125. ATRX185 and ATRX125 form distinct multisubunit complexes in fly embryo. The ATRX185 complex comprises p185 and heterochromatin protein HP1a. Consistently, ATRX185 but not ATRX125 is highly concentrated in pericentric beta-heterochromatin of the X chromosome in larval cells. HP1a strongly stimulates biochemical activities of ATRX185 in vitro. Conversely, ATRX185 is required for HP1a deposition in pericentric beta-heterochromatin of the X chromosome. The loss of function allele of the ATRX/XNP gene and mutant allele that does not express p185 are strong suppressors of position effect variegation. These results provide evidence for essential biological functions of Drosophila ATRX in vivo and establish ATRX as a major determinant of pericentric beta-heterochromatin identity. [ABSTRACT FROM AUTHOR]

Abstract: β-Lactams bearing a Ph2CF substituent at the C(4)-atom were synthesized from N-alkyl-2-fluoro-3,3-diphenylaziridines. The transformation was realized using SbF3-mediated isomerization of the monofluoroaziridines to fluorinated aldimines, followed by Staudinger reaction with ketenes. It was shown that this reaction sequence can be performed as a one-pot procedure. [Copyright &y& Elsevier]

The Cover Feature illustrates light‐driven oxygen reduction to hydrogen peroxide catalyzed by polymerized Ni–salen complexes. More information can be found in the Communication by A. S. Konev et al on page 3138 in Issue 21, 2018 (DOI: 10.1002/celc.201800846). [ABSTRACT FROM AUTHOR]

Back Cover: Modern gadgets consume tons of Li‐ion batteries, which are mostly based on hazardous inorganic materials. Nickel‐salen‐type organometallic polymers are prospective cathode materials, which alleviate the impact on the environment yet are powerful enough to supply energy for most portable devices. More information can be found in article number 1700361 by Svetlana N. Eliseeva, Elena V. Alekseeva, Anatoliy A. Vereshchagin, Alexey I. Volkov, Petr S. Vlasov, Alexander S. Konev, and Oleg V. Levin*. [ABSTRACT FROM AUTHOR]

Drosophila melanogaster telomeres have two DNA domains: a terminal array of retrotransposons and a subterminal repetitive telomere-associated sequence (TAS), a source of telomere position effect (TPE). We reported previously that deletion of the 2L TAS array leads to dominant suppression of TPE by stimulating in trans expression of a telomeric transgene. Here, we compared the transcript activities of a w transgene inserted between the retrotransposon and TAS arrays at the 2L telomere in genotypes with different lengths of the 2L TAS. In contrast to individuals bearing a wild-type 2L homologue, flies with a TAS deficiency showed a significant increase in the level of telomeric w transcript during development, especially in pupae. Moreover, we identified a read-through w transcript initiated from a retrotransposon promoter in the terminal array. Read-through transcript levels also significantly increased with the presence of a 2L TAS deficiency in trans, indicating a stimulating force of the TAS deficiency on retrotransposon promoter activity. The read-through transcript contributes to total w transcript, although most w transcript originates at the w promoter. While silencing of transgenes in nonhomologous telomeres is suppressed by 2L TAS deficiencies, suggesting a global effect, the overall level of HeT-A transcripts is not increased under similar conditions. [ABSTRACT FROM AUTHOR]

The Chromatin Accessibility Complex (CHRAC) consists of the ATPase ISWI, the large ACF1 subunit and a pair of small histone-like proteins, CHRAC-14/16. CHRAC is a prototypical nucleosome sliding factor that mobilizes nucleosomes to improve the regularity and integrity of the chromatin fiber. This may facilitate the formation of repressive chromatin. Expression of the signature subunit ACF1 is restricted during embryonic development, but remains high in primordial germ cells. Therefore, we explored roles for ACF1 during Drosophila oogenesis. ACF1 is expressed in somatic and germline cells, with notable enrichment in germline stem cells and oocytes. The asymmetrical localization of ACF1 to these cells depends on the transport of the Acf1 mRNA by the Bicaudal-D/Egalitarian complex. Loss of ACF1 function in the novel Acf1 7 allele leads to defective egg chambers and their elimination through apoptosis. In addition, we find a variety of unusual 16-cell cyst packaging phenotypes in the previously known Acf1 1 allele, with a striking prevalence of egg chambers with two functional oocytes at opposite poles. Surprisingly, we found that the Acf1 1 deletion – despite disruption of the Acf1 reading frame – expresses low levels of a PHD-bromodomain module from the C-terminus of ACF1 that becomes enriched in oocytes. Expression of this module from the Acf1 genomic locus leads to packaging defects in the absence of functional ACF1, suggesting competitive interactions with unknown target molecules. Remarkably, a two-fold overexpression of CHRAC (ACF1 and CHRAC-16) leads to increased apoptosis and packaging defects. Evidently, finely tuned CHRAC levels are required for proper oogenesis. [ABSTRACT FROM AUTHOR]

We generated mutant alleles of Drosophila melanogaster in which expression of the linker histone H1 can be down-regulated over a wide range by RNAi. When the H1 protein level is reduced to ◻420% of the level in wild-type larvae, lethality occurs in the late larval - pupal stages of development. Here we show that H1 has an important function in gene regulation within or near heterochromatin. It is a strong dominant suppressor of position effect variegation (PEV). Similar to other suppressors of PEV, H1 is simultaneously involved in both the repression of euchromatic genes brought to the vicinity of pericentric heterochromatin and the activation of heterochromatic genes that depend on their pericentric localization for maximal transcriptional activity. Studies of H1-depleted salivary gland polytene chromosomes show that H1 participates in several fundamental aspects of chromosome structure and function. First, H1 is required for heterochromatin structural integrity and the deposition or maintenance of major pericentric heterochromatin-associated histone marks, including H3K9Me2 and H4K20Me2. Second, H1 also plays an unexpected role in the alignment of endoreplicated sister chromatids. Finally, H1 is essential for organization of pericentric regions of all polytene chromosomes into a single chromocenter. Thus, linker histone H1 is essential in Drosophila and plays a fundamental role in the architecture and activity of chromosomes in vivo. [ABSTRACT FROM AUTHOR]