Inhomogeneous broadening of the exciton band in optical absorption spectra of InP/ZnS nanocrystals

In this work, we have simulated the processes of broadening the first exciton band in optical absorption spectra (OA) for InP/ZnS ensembles of colloidal quantum dots (QDs). A phenomenological model has been proposed that takes into account the effects of the exciton–phonon interaction, and allows one to analyze the influence of the static and dynamic types of atomic disorder on the temperature changes in the spectral characteristics in question. To vary the degree of static disorder in the model system, we have used a parameter δ, which characterizes the QD dispersion in size over the ensemble. We have also calculated the temperature shifts of the maxima and changes in the half-width for the exciton peaks in single nanocrystals (δ = 0), as well as for the integrated OA bands in the QD ensembles with different values of δ = 0.6–17%. The simulation results and the OA spectra data measured for InP/ZnS nanocrystals of 2.1 nm (δ = 11.1%) and 2.3 nm (δ = 17.3%), are in good mutual agreement in the temperature range of 6.5 K–RT. It has been shown that the contribution of static disorder to the observed inhomogeneous broadening of the OA bands for the QDs at room temperature exceeds 90%. The computational experiments performed indicate that the temperature shift of the maximum for the integrated OA band coincides with that for the exciton peak in a single nanocrystal. In this case, a reliable estimate of the parameters of the fundamental exciton–phonon interaction can be made. Simultaneously, the values of the specified parameters, calculated from the temperature broadening of the OA spectra, can be significantly different from the true ones due to the effects of static atomic disorder in real QD ensembles. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This research was supported by RFBR according to the research project № 18-32-00664 and Act 211 Government of the Russian Federation, contract no. 02.A03.21.0006. I.W. thanks the Minobrnauki initiative research project № 16.5186.2017/8.9 for support

Search for the edge-on galaxies using an artificial neural network

We present an application of an artificial neural network methodology to a modern wide-field sky survey Pan-STARRS1 in order to build a high-quality sample of disk galaxies visible in edge-on orientation. Such galaxies play an important role in the study of the vertical distribution of stars, gas and dust, which is usually not available to study in other galaxies outside the Milky Way. We give a detailed description of the network architecture and the learning process. The method demonstrates good effectiveness with detection rate about 97\% and it works equally well for galaxies over a wide range of brightnesses and sizes, which resulted in a creation of a catalogue of edge-on galaxies with $10^5$ of objects. The catalogue is published on-line with an open access.Comment: 15 pages, 11 figure

Synthesis and Characterization of Copolymers of Lantanide Complexes with Styrene

Сopolymers of 2-methyl-5-phenylpentene-1-dione-3,5 with styrene in ratio 5:95, which containing Eu, Yb and Eu, Yb with 1,10-phenanthroline were synthesized at the first time. The luminescence spectra of obtained metal complexes and copolymers in solutions, films and solid state are investigated and analyzed. The solubilization of β-diketonate complexes with phenanthroline was shown to change luminescence intensity in such complexes. Obtained copolymers can be used as potential materials for organic light-emitting devices

Importance of serous intraepithelial ovarian tubal carcinomas in the occurrence of "high-grade" serous carcinomas and / or peritoneal serous carcinomas of unknown primary origin.

Studies of the recent decades on serous pelvic adenocarcinomas in women have set the goal of distinguishing between two diagnostic units: "low-grade" and "high-grade" carcinomas. The predecessor of the "low-grade" variant (type I) is considered to be a borderline serous tumor / atypical proliferative serous tumor (8442/1), which according to the International Classification of Diseases for Oncology ICD-O 2013 of the female reproductive system refers to non-specific, borderline tumors and tumors with unpredictable clinical behavior. The predecessors of the “high-grade” variant (type II) are serous tubular intraepithelial carcinomas (in situ) or “high-grade” serous invasive tubal carcinomas, since they have the TP53 mutation identical to “high-grade” ovarian carcinoma, an aberrant p53 protein expression, high proliferative activity, and significant genomic instability. In addition, according to the carcinogenesis of "high-grade" serous ovarian carcinoma with metastases to the peritoneum, it can also be interpreted as "pelvic high-grade serous carcinoma". A retrospective analysis of the histological, morphometric and immunohistochemical characteristics of the biopsy material of 31 women aged from 28 to 76 years (mean 57.32±11.54; median 57), divided into 3 groups, was carried out. Group 1: 14 observations of the tubal epithelium (8 tubes without pathological changes (subgroup 1a) and 6 with signs of intraepithelial neoplasia (subgroup 1b); group 2: 12 cases of serous adenocarcinoma of the ovary of the “high-grade” variant; group 3: 6 metastatic peritoneal serous carcinoma without a known primary site. Results. Group immunophenotypes showed uniformity in the expression of markers CK7 (+, +/-), CK20 (-), WT-1 (+), CA125 (+, +/-), with an affinity to distal uterine tube fragments. The expression of p53 in all groups with signs of carcinomas (compared with the control subgroup 1a without atypia) was divided into two options - negative samples and samples with overexpression, where no statistically significant difference was found (p>0.05), which is possibly a single way of carcinogenesis. The morphometric study revealed a significant difference in the area of the nuclei between group 3 and the first three groups (1a, 1b, 2), which indicates the similarity of ovarian and tubal neoplasias and uterine tube epithelium. The number of intranuclear reactions with ER and PGR progressively decreased from group 1 to group 3, with an increase in cases with ER (+/-) / PGR (+/- or -) to 50% in group 3, which greatly complicated the diagnostic search for unknown carcinomas of primary localization. HER-2-new expression revealed a possible amplification (gradation 2 + / 3 +) only in group 2 at the level of 16.67% and in group 3 at the level of 33.33%

Temperature dependence of self-trapped exciton luminescence in nanostructured hafnia powder

The intrinsic optical properties and peculiarities of the energy structure of hafnium dioxide largely determine the prospects for applying the latter in new generation devices of optoelectronics and nanoelectronics. In this work, we have studied the diffuse reflectance spectra at room temperature for a nominally pure nanostructured $HfO_2$ powder with a monoclinic crystal structure and, as well its photoluminescence in the temperature range of 40 - 300 K. We have also estimated the bandgap $E_g$ under the assumption made for indirect (5.31 eV) and direct (5.61 eV) allowed transitions. We have detected emission with a 4.2 eV maximum at T < 200 K and conducted an analysis of the experimental dependencies to evaluate the activation energies of thermal quenching (140 meV) and enhancement (3 meV) processes. Accounting for both the temperature behavior of the spectral characteristics and the estimation of the Huang-Rhys factor S >> 1 has shown that radiative decay of self-trapped excitons forms the mechanism of the indicated emission. In this case, the localization is mainly due to the interaction of holes with active vibrational modes of oxygen atoms in non-equivalent ($O_{3f}$ and $O_{4f}$) crystal positions. Thorough study of the discussed excitonic effects can advance development of hafnia-based structures with a controlled optical response.Comment: 21 pages, 7 figures, 2 tables, 56 references. Keywords: hafnium dioxide, self-trapped exciton, F-center, thermal quenching of luminescence, luminescence enhacement, Huang-Rhys factor, effective phonon energy, bandgap widt

ДЕЯКІ ПИТАННЯ СУДОВОЇ ПСИХОЛОГІЧНОЇ ЕКСПЕРТИЗИ ПОТЕРПІЛИХ ВІД ДОМАШНЬОГО НАСИЛЬСТВА (оглядова стаття)

The main aspects of forensic psychological examination of a victim while criminal proceedings listed in the Unified Register of pre-trial investigations according to criminal offense elements provided for by Article 126-1 of the Criminal Code of Ukraine are considered. Attention is paid to legal and theoretical-methodological grounds for the appointment and conduct of this subject type of forensic psychological examination. The relationship between the concepts of “violence”, “aggression” and “coercion” is defined, content and main forms of violence are revealed. An attempt is made to summarize empirical evidence results of this type of forensic examinations. The study on women (victims of domestic violence) psychology is emphasized. The necessity in developing methodical recommendations as to forensic psychological examination of victims in the course of domestic violence investigations is proved.Розглянуто основні аспекти проведення судової психологічної експертизи потерпілої особи у кримінальних провадженнях, внесених до Єдиного реєстру досудових розслідувань за ознаками кримінального правопорушення, передбаченого ст. 1261 Кримінального кодексу України. Приділено увагу юридичним і теоретично-методологічним підставам призначення та проведення цього виду судової психологічної експертизи. Визначено співвідношення понять «насильство», «агресія» і «примушування», розкрито зміст та основні форми насильства. Зроблено спробу узагальнити результати емпіричного досвіду проведення експертиз цього виду. Акцентовано увагу на дослідженні питання психології жінки, яка потерпає від домашнього насильства. Обґрунтовано необхідність розроблення методичних рекомендацій щодо психологічного дослідження потерпілих під час розслідування кримінальних проваджень, пов’язаних із домашнім насильством

Near infrared emission bands of solid Nitrogen

New results on the study of radiation effects in solid nitrogen and N$_2$-doped Ne matrix are presented with a focus on the so-called $\gamma$-line origin. The irradiation was carried out in dc regime with an electron beam of subthreshold energy. Relaxation dynamics was monitored by emission spectroscopy - cathodoluminescence (CL) and nonstationary luminescence (NsL), along with current activation spectroscopy. Thermally stimulated luminescence (TSL) and exoelectron emission (TSEE) of pure nitrogen and N$_2$ in the Ne matrix were measured in a correlated manner. Three emission bands were recorded in the NIR CL spectra of solid N$_2$: 794, 802, and 810 nm. The band at 810 nm was detected for the first time. These three bands are characterized by similar behavior and form molecular series with spacing between adjacent vibrational energy levels of the ground state of 125 cm$^{-1}$ and 123 cm$^{-1}$. These data cast doubt on the recently made assumption that the $\gamma$-line is attributed to the emission of the nitrogen anion N$^-$ [19]. The processes of an electron attachment and neutralization of positively charged species are discussed. It has been established that the $\gamma$-line in the TSL spectra of pure nitrogen and N$_2$-doped Ne matrix correlates with TSEE currents and recombination emission of O$^+$, N$_2^+$, and N$_4^+$ ions, which indicates its connection with the neutralization reaction. The measurement of NsL supported this conclusion. A new possible assignment of the $\gamma$-line and its satellites to the emission of tetranitrogen N$_4$ is discussed.Comment: 15 pages, 7 figures, 67 reference

Analysis of the level of expression of pancytokeratins in epithelial and granulocellular tumors of the ovaries.

Differential diagnosis of ovarian neoplasms is carried out among groups of epithelial and granulocellular tumors and remains an actual problem of oncogynecology. In general, epithelial tumors  occur (up to 60%), but granulocellular cell tumors account for up to 5% of all ovarian neoplasia. Materials and methods. A retrospective study of 43 observations of ovarian tumor lesions over the period of January-December 2017 was conducted in the work. The aim of the study was to analyze the complex of morphological and immunohistochemical characteristics of Cytokeratin, Pan AE1 / AE3 - negative phenotypes and Cytokeratin, Pan AE1 / AE3 - positive phenotypes of ovarian neoplasia to improve diagnostic algorithms. Results. The phenotype of epithelial ovarian tumors in 100% of observations corresponds to pancytokeratin Cytokeratin, Pan AE1 / AE3 "+", in its turn the phenotype of granulocellular tumors basically responded to expression of the Cytokeratin marker, Pan AE1 / AE3 "-" in 62.5%; and the variant in the part of the cells "+" / "-" Cytokeratin, Pan AE1 / AE3 was found in 37.5% of granulocellular tumors, regardless of their malignant potential. Thus, granulocellular tumors have variable expression of the Cytokeratin marker, Pan AE1 / AE3 and require the inclusion of other diagnostic IGH markers in the primary panel