On the Cauchy Problem for the Korteweg-de Vries Equation with Steplike Finite-Gap Initial Data I. Schwartz-Type Perturbations

We solve the Cauchy problem for the Korteweg-de Vries equation with initial conditions which are steplike Schwartz-type perturbations of finite-gap potentials under the assumption that the respective spectral bands either coincide or are disjoint.Comment: 29 page

ЭКСТРАКЦИОННО-ФЛУОРИМЕТРИЧЕСКОЕ ОПРЕДЕЛЕНИЕ ХЛОРОФИЛЛА «А» В ПРИРОДНЫХ ВОДАХ

The assessment methods of chlorophyll «а» in the natural waters have been analyzed. This pigment of phytoplankton is the main indicator of the primary bioproductivity and trophicity of the reservoir.  The key spectrometric methods of determination were compared, and their advantages and disadvantages were discussed.  The application features of different types of spectrometric determination of the analyte from classical spectrophotometric methods to remote sensing of water bodies were considered.  The preference was shown for the determination of chlorophyll by the fluorescent methods, which were used in different implementation variations.  The method of extraction-fluorescent determination of chlorophyll «а» was substantiated and implemented after the chlorophyll extraction from the water with chloroform and measuring the fluorescence intensity at λexc = 418 nm and λlum = 675 nm.  The results of the chlorophyll «а» determination were compared using the standardized spectrophotometric and the developed techniques for the model and real water samples.  It was educed that in the area of low concentrations of chlorophyll «а» (0.05 μg of analyte in 1000 cm3 of water) the analytical signal was recorded only by the fluorimetric method, while in the area of higher concentrations (0.2 μg of analyte in 1000 cm3 of water) the standardized spectrophotometric method produced the overestimated results.  The developed method for the extraction-fluorimetric determination of chlorophyll «а» in the natural waters (both fresh and marine) was metrologically certified and put into the register of the Federal Information Fund for ensuring the uniformity of measurements.Key words: chlorophyll «а» , extraction - fluorimetric determination, trophicity of the reservoirDOI: http://dx.doi.org/10.15826/analitika.2019.23.3.001(Russian)Z. A. Temerdasheva1, L. F. Pavlenko2, Ya. S. Ermakova1,2, I. G. Korpakova1,             B. D. Eletskii1 1Department of Chemistry and High Technology, Kuban State University, Krasnodar, 350040, Russian Federation2Azov-Black Sea branch of VNIRO (“AzNIIRKH”), Rostov-on-Don, 344002, Russian FederationВ статье проводится анализ методов определения хлорофилла «а» в природных водах – основного пигмента фитопланктона, являющегося индикатором первичной биопродуктивности и трофности водоема. Приводится сравнительная характеристика спектрометрических методов определения, их достоинства и недостатки. Обсуждаются особенности применения различных видов спектрометрического определения аналита: от классических спектрофотометрических до методов дистанционного зондирования водоемов. Показана предпочтительность определения хлорофилла флуоресцентными методами, которые используются в различных вариантах реализации. Обоснована и реализована методика экстракционно-флуоресцентного определения хлорофилла «а» после экстракции его из воды хлороформом и измерении интенсивности флуоресценции при λвозб = 418 нм и λлюм = 675 нм. Проведено сравнение результатов определения хлорофилла «а» стандартизированной спектрофотометрической и разработанной методиками на модельных и реальных пробах воды.  Показано, что в области низких концентраций хлорофилла «а» (0,05 мкг аналита в 1000 см3 воды) аналитический сигнал регистрируется только флуориметрическим методом, а в области более высоких концентраций (0.2 мкг аналита в 1000 см3 воды) спектрофотометрическая стандартизированная методика дает завышенные результаты. Разработанная методика экстракционно-флуориметрического определения хлорофилла «а» в природных водах (пресных и морских) метрологически аттестована и внесена в реестр Федерального информационного фонда по обеспечению единства измерений.Ключевые слова. Хлорофилл «а» , экстракционно-флуориметрическое определение, трофность водоемов.DOI: http://dx.doi.org/10.15826/analitika.2019.23.3.00

BIOLOGICAL EFFECTS OF THE NEW SILVER-CONTAINING POLYMER NANOCOMPOSITE

In the materials there are presented, results of the synthesis and biological testing of the new nanocomposite which, contains silver nanoparticles incapsulated. in the synthetic polymer poly-1-vinyl-1,2,4-triazole. The synthesis method, of silvercontaining polymere nanocomposite is shown. With the use of modern equipment evidence of the nanocomposite with the size of 2-10 nm silver production, are substinated. It was revealed, that the new nanocomposite causes slight changes in the tissue structure of experimental animals internal organs and biochemical shift that is characteristic for the compensatory-adaptive reactions development. There are presented, the results of the silver nanoparticles distribution, mainly in the kidney and. liver tissue

СИНТЕЗ И ХАРАКТЕРИЗАЦИЯ ТРИМЕТИЛ(ФЕНИЛ)СИЛАНА — ПРЕДШЕСТВЕННИКА ДЛЯ ГАЗОФАЗНЫХ ПРОЦЕССОВ ОСАЖДЕНИЯ ПЛЕНОК SiCx : H

The technique of synthesis and purification of trimethyl(phenyl)silane PhSiMe3, allowing to obtain the product with high yield. Individuality of the product was confirmed by elemental analysis for C, H, Si. IR, UV and 1H NMR–spectroscopic studies, defined its spectral characteristics. Complex thermal analysis and thermogravimetric defined thermoanalytical behavior effects of PhSiMe3 in an inert atmosphere. Tensimetric studies have shown that the compound has sufficient volatility and thermal stability for use as a precursor in the process of chemical vapor deposition (CVD). The composition and temperature limits of the possible crystalline phase complexes in equilibrium with the gas phase of different composition has been determed by method of thermodynamic modeling. Calculated CVD diagrams allow us to select the optimum conditions of film deposition. The possibility of using trimethyl(phenyl)silane in CVD processes for producing dielectric films of hydrogenated silicon carbide has been demonstrated. Разработана методика синтеза и очистки триметил(фенил)силана PhSiMe3, позволяющая получать целевой продукт с высоким выходом. Индивидуальность соединения подтверждена элементным анализом на C, H, Si. ИК−, УФ− и ЯМР−спектроскопическими исследованиями (1Н, 13C, 29Si) определены его спектральные характеристики. С помощью комплексного термического анализа определены термоаналитические и термогравиметрические эффекты поведения PhSiMe3 в инертной атмосфере. На основе данных тензометрических исследований показано, что это соединение обладает достаточной летучестью и термической устойчивостью для использования в качестве прекурсора в процессах химического осаждения из газовой фазы (CVD). Методом термодинамического моделирования определен состав и температурные границы возможных кристаллических фазовых комплексов в равновесии с газовой фазой различного состава. Рассчитанные CVD− диаграммы позволяют выбрать оптимальные условия процессов осаждения из газовой фазы пленок. Показана возможность использования PhSiMe3 в процессах CVD для получения диэлектрических пленок гидрогенизированного карбида кремния.

A large scale hearing loss screen reveals an extensive unexplored genetic landscape for auditory dysfunction

The developmental and physiological complexity of the auditory system is likely reflected in the underlying set of genes involved in auditory function. In humans, over 150 non-syndromic loci have been identified, and there are more than 400 human genetic syndromes with a hearing loss component. Over 100 non-syndromic hearing loss genes have been identified in mouse and human, but we remain ignorant of the full extent of the genetic landscape involved in auditory dysfunction. As part of the International Mouse Phenotyping Consortium, we undertook a hearing loss screen in a cohort of 3006 mouse knockout strains. In total, we identify 67 candidate hearing loss genes. We detect known hearing loss genes, but the vast majority, 52, of the candidate genes were novel. Our analysis reveals a large and unexplored genetic landscape involved with auditory function

Epigallocatechin-3-gallate suppresses the expression of HSP70 and HSP90 and exhibits anti-tumor activity in vitro and in vivo

<p>Abstract</p> <p>Background</p> <p>Epigallocatechin-3-gallate (EGCG), one of the major catechins in green tea, is a potential chemopreventive agent for various cancers. The aim of this study was to examine the effect of EGCG on the expression of heat shock proteins (HSPs) and tumor suppression.</p> <p>Methods</p> <p>Cell colony formation was evaluated by a soft agar assay. Transcriptional activity of HSP70 and HSP90 was determined by luciferase reporter assay. An EGCG-HSPs complex was prepared using EGCG attached to the cyanogen bromide (CNBr)-activated Sepharose 4B. <it>In vivo </it>effect of EGCG on tumor growth was examined in a xenograft model.</p> <p>Results</p> <p>Treatment with EGCG decreased cell proliferation and colony formation of MCF-7 human breast cancer cells. EGCG specifically inhibited the expression of HSP70 and HSP90 by inhibiting the promoter activity of HSP70 and HSP90. Pretreatment with EGCG increased the stress sensitivity of MCF-7 cells upon heat shock (44°C for 1 h) or oxidative stress (H₂O₂, 500 μM for 24 h). Moreover, treatment with EGCG (10 mg/kg) in a xenograft model resulted in delayed tumor incidence and reduced tumor size, as well as the inhibition of HSP70 and HSP90 expression.</p> <p>Conclusions</p> <p>Overall, these findings demonstrate that HSP70 and HSP90 are potent molecular targets of EGCG and suggest EGCG as a drug candidate for the treatment of human cancer.</p

EMIC wave events during the four GEM QARBM challenge intervals

This paper presents observations of EMIC waves from multiple data sources during the four GEM challenge events in 2013 selected by the GEM “Quantitative Assessment of Radiation Belt Modeling” focus group: March 17‐18 (Stormtime Enhancement), May 31‐June 2 (Stormtime Dropout), September 19‐20 (Non‐storm Enhancement), and September 23‐25 (Non‐storm Dropout). Observations include EMIC wave data from the Van Allen Probes, GOES, and THEMIS spacecraft in the near‐equatorial magnetosphere and from several arrays of ground‐based search coil magnetometers worldwide, as well as localized ring current proton precipitation data from low‐altitude POES spacecraft. Each of these data sets provides only limited spatial coverage, but their combination shows consistent occurrence patterns and reveals some events that would not be identified as significant using near‐equatorial spacecraft alone. Relativistic and ultrarelativistic electron flux observations, phase space density data, and pitch angle distributions based on data from the REPT and MagEIS instruments on the Van Allen Probes during these events show two cases during which EMIC waves are likely to have played an important role in causing major flux dropouts of ultrarelativistic electrons, particularly near L* ~ 4.0. In three other cases identifiable smaller and more short‐lived dropouts appeared, and in five other cases these waves evidently had little or no effect

A Second-Generation Device for Automated Training and Quantitative Behavior Analyses of Molecularly-Tractable Model Organisms

A deep understanding of cognitive processes requires functional, quantitative analyses of the steps leading from genetics and the development of nervous system structure to behavior. Molecularly-tractable model systems such as Xenopus laevis and planaria offer an unprecedented opportunity to dissect the mechanisms determining the complex structure of the brain and CNS. A standardized platform that facilitated quantitative analysis of behavior would make a significant impact on evolutionary ethology, neuropharmacology, and cognitive science. While some animal tracking systems exist, the available systems do not allow automated training (feedback to individual subjects in real time, which is necessary for operant conditioning assays). The lack of standardization in the field, and the numerous technical challenges that face the development of a versatile system with the necessary capabilities, comprise a significant barrier keeping molecular developmental biology labs from integrating behavior analysis endpoints into their pharmacological and genetic perturbations. Here we report the development of a second-generation system that is a highly flexible, powerful machine vision and environmental control platform. In order to enable multidisciplinary studies aimed at understanding the roles of genes in brain function and behavior, and aid other laboratories that do not have the facilities to undergo complex engineering development, we describe the device and the problems that it overcomes. We also present sample data using frog tadpoles and flatworms to illustrate its use. Having solved significant engineering challenges in its construction, the resulting design is a relatively inexpensive instrument of wide relevance for several fields, and will accelerate interdisciplinary discovery in pharmacology, neurobiology, regenerative medicine, and cognitive science