On the nature of the Be star HR 7409 (7 Vul)

HR 7409 (7 Vul) is a newly identified Be star possibly part of the Gould Belt and is the massive component of a 69-day spectroscopic binary. The binary parameters and properties of the Be star measured using high-dispersion spectra obtained at Ondrejov Observatory and at Rozhen Observatory imply the presence of a low mass companion (~ 0.5-0.8 M_sun). If the pair is relatively young (<50-80 Myr), then the companion is a K V star, but, following another, older evolutionary scenario, the companion is a horizontal-branch star or possibly a white dwarf star. In the latter scenario, a past episode of mass transfer from an evolved star onto a less massive dwarf star would be responsible for the peculiar nature of the present-day, fast-rotating Be star.Comment: Accepted for publication in MNRA

FBILI method for the two-level atom line formation in media with low velocity fields

In this paper we generalized the fast convergent Forth-and-Back Implicit Lambda Iteration (FBILI) method to the solution of the two-level atom line transfer problems in media with low velocity fields using the observer’s reference frame. In order to test the accuracy and the convergence properties of the method we solved several astrophysically important benchmark problems of the NLTE line formation: in a plan-parallel differentially expanding medium of finite thickness, and in spherically symmetric stellar atmospheres, both static and expanding. We compared our solutions with those obtained by other authors using different numerical methods. [Projekat Ministarstva nauke Republike Srbije, br. 176004: Stellar Physics

Antitumor effect of mifepristone on human endometrial stromal cell line

Background/Aim. The main cause for development of endo-metrial hyperplasia is unopposed effect of estrogen on endome-trial cells. The aim of our study was to investigate and compare cytotoxic and apoptotic effects of mifepristone on human en-dometrial stromal cell line for the first time. Both percentage of cytotoxic and apoptotic cells were determined after 24 h treat-ment with different doses of mifepristone. Methods. The per-centage of cytotoxic cell was evaluated by viability assay while the percentage of apoptotic cells was determined using flow cytome-try. Determination of apoptotic effects was confirmed using im-munofluorescence method determining expression and localiza-tion of active Bax and Bcl-2 proteins. Results. Our results indi-cated that mifepristone induced cytotoxic and apoptotic effect on human endometrial stromal cell line (ThESC) through chang-es in expression level of Bcl-2 and active Bax proteins. Conclu-sion. Cytotoxic and pro-apoptotic effects of mifepristone on human endometrial stromal cell line in vitro was investigated in this study for the first time. It is crucial to point out that mifepris-tone expressed both cytotoxic and pro-apoptotic effect on ThESC cell line. Our results may contribute to determination of localization and expression level of the crucial proteins involved in apoptosis in ThESC cell line after the treatment with the low-est cytotoxic doses of mifepristone

Antitumor effects of vanillin based chalcone analogs in vitro

© 2020 Polish Pharmaceutical Society. All rights reserved. Chalcones, as a large group of organic compounds, are widely implemented in various types of anticancer therapeutics. These plant metabolites are present in fruits, vegetables, spices, and have anti-tumor, antiinflammation, immunomodulation, antibacterial and anti-oxidative activities, as well as many other pharmacological and biological effects. The aim of the present study was to investigate cytotoxic effects, type of cell death and mechanism of action of the newly synthesized vanillin based chalcone analogs, (CH1) and (CH2) on human colon cancer HCT-116 and noncancerous (control) MRC-5 cell lines. In order to compare the effects of vanillin based chalcone analogs on investigated cell lines, as reference substances cisplatin (cisPt) and dehydrozingerone (DHZ) were used. Investigation of antitumor effect of chalcone analogs on HCT-116 cells was carried out by three methods MTT assay, flow cytometry and immunofluorescence analysis. The result of our investigation indicated that newly synthesized vanillin based chalcone analogs expressed powerful antitumor effect on cancer cells (HCT-116 cell line), while their effect on healthy cells (MRC-5 cell line) was not statistically significant. Vanillin based chalcone analogs caused overexpression and activation of mitochondrial Bax protein and caspase-3 in HCT-116 cells, indicating that their mechanism of antitumor action was mediated through activation of the inner apoptotic pathway. These results indicate possible usefulness of CH1 and CH2 in antitumor therapy whether through its direct cytotoxic effect or as adjuvant therapy. Our results indicate possible usefulness of CH1 and CH2 vanillin based chalcone analogs in antitumor therapy