Correlations between X-ray Spectral and Timing Characteristics in Cyg X-2

Correlations between the quasi-periodic oscillations (QPOs) and the spectral power-law index have been reported for a number of black hole candidate sources and for four neutron star (NS) sources, 4U 0614+09, 4U 1608-52, 4U 1728-34 and Sco X-1. An examination of QPO frequencies and index relationship in Cyg X-2 is reported herein. The RXTE spectrum of Cyg X-2 can be adequately represented by a simple two-component model of Compton up-scattering with a soft photon electron temperature of about 0.7 keV and an iron K-line. Inferred spectral power-law index shows correlation with the low QPO frequencies. We find that the Thomson optical depth of the Compton cloud (CC) tau, in framework of spherical geometry, is in the range of ~4-6, which is consistent with the neutron star's surface being obscured. The NS high frequency pulsations are presumably suppressed as a result of photon scattering off CC electrons because of such high values of tau. We also point out a number of similarities in terms timing (presence of low and high frequency QPOs) and spectral (high CC optical depth and low CC plasma temperature) appearances between Cyg X-2 and Sco X-1.Comment: 7 pages, 4 figures, accepted for publication in ApJ (October 1, 2007, v667n2 issue

Author Correction: DNA damage in circulating leukocytes measured with the comet assay may predict the risk of death (Scientific Reports, (2021), 11, 1, (16793), 10.1038/s41598-021-95976-7)

Link to the corrected article: [https://farfar.pharmacy.bg.ac.rs/handle/123456789/3944

DNA damage in circulating leukocytes measured with the comet assay may predict the risk of death

The comet assay or single cell gel electrophoresis, is the most common method used to measure strand breaks and a variety of other DNA lesions in human populations. To estimate the risk of overall mortality, mortality by cause, and cancer incidence associated to DNA damage, a cohort of 2,403 healthy individuals (25,978 person-years) screened in 16 laboratories using the comet assay between 1996 and 2016 was followed-up. Kaplan–Meier analysis indicated a worse overall survival in the medium and high tertile of DNA damage (p < 0.001). The effect of DNA damage on survival was modelled according to Cox proportional hazard regression model. The adjusted hazard ratio (HR) was 1.42 (1.06–1.90) for overall mortality, and 1.94 (1.04–3.59) for diseases of the circulatory system in subjects with the highest tertile of DNA damage. The findings of this study provide epidemiological evidence encouraging the implementation of the comet assay in preventive strategies for non-communicable diseases.This article has been corrected. Link to the correction: [https://farfar.pharmacy.bg.ac.rs/handle/123456789/3975

Phase synthesis of a wave beam field that provides maximization of the transmitted power

The problem of power transmission via a long microwave beam is usually solved by means of the creation of the field that falls at the antenna edges and its focusing toward the rectenna center. It is shown that phase synthesis may be realized with the use of an extra distribution of the radiated field phase. That optimal phase correction provides some power increase when the uniform law describes a radiated field distribution

Functional state of the blood coagulation system in postsurgery period in patients with malignant tumors of the GI tract

The present paper analyzes changes in coagulation system markers in 64 patients with malignant tumors of the GI in surgical treatment. Results obtained when using parameters of the expanded coagulogram and a new global hemostatic assessment test with the use of Thrombodynamics recorder T2 have been evaluated. Based on the findings, we have developed models for predicting postoperative venous thrombosis and compared different methods for the coagulation system examinations. The thrombodynamics test allows us to assess the state of thrombotic readiness in the postoperative period in 26.56% of patients with GI cancer upon the standard anticoagulant prevention. High levels of the thrombinemia markers and hypercoagulation at the fibrin clot growth rate have been detected after the surgery. Correlation between the plasma fibrinogen levels and the fibrin clot density has been observed. Therefore, the proposed highly sensitive global assessment test of the hemostatic system allows us to detect hypercoagulation and evaluate the efficacy of a preventive dose of low molecular weight heparin (LMWH)

De novo assembling and primary analysis of genome and transcriptome of gray whale Eschrichtius robustus

Abstract Background Gray whale, Eschrichtius robustus (E. robustus), is a single member of the family Eschrichtiidae, which is considered to be the most primitive in the class Cetacea. Gray whale is often described as a “living fossil”. It is adapted to extreme marine conditions and has a high life expectancy (77 years). The assembly of a gray whale genome and transcriptome will allow to carry out further studies of whale evolution, longevity, and resistance to extreme environment. Results In this work, we report the first de novo assembly and primary analysis of the E. robustus genome and transcriptome based on kidney and liver samples. The presented draft genome assembly is complete by 55% in terms of a total genome length, but only by 24% in terms of the BUSCO complete gene groups, although 10,895 genes were identified. Transcriptome annotation and comparison with other whale species revealed robust expression of DNA repair and hypoxia-response genes, which is expected for whales. Conclusions This preliminary study of the gray whale genome and transcriptome provides new data to better understand the whale evolution and the mechanisms of their adaptation to the hypoxic conditions

DNA strand break levels in cryopreserved mononuclear blood cell lines measured by the alkaline comet assay:results from the hCOMET ring trial

The comet assay is widely used in biomonitoring studies for the analysis of DNA damage in leukocytes and peripheral blood mononuclear cells. Rather than processing blood samples directly, it can be desirable to cryopreserve whole blood or isolated cells for later analysis by the comet assay. However, this creates concern about artificial accumulation of DNA damage during cryopreservation. In this study, 10 laboratories used standardized cryopreservation and thawing procedures of monocytic (THP-1) or lymphocytic (TK6) cells. Samples were cryopreserved in small aliquots in 50% foetal bovine serum, 40% cell culture medium, and 10% dimethyl sulphoxide. Subsequently, cryopreserved samples were analysed by the standard comet assay on three occasions over a 3-year period. Levels of DNA strand breaks in THP-1 cells were increased (four laboratories), unaltered (four laboratories), or decreased (two laboratories) by long-term storage. Pooled analysis indicates only a modest positive association between storage time and levels of DNA strand breaks in THP-1 cells (0.37% Tail DNA per year, 95% confidence interval: -0.05, 0.78). In contrast, DNA strand break levels were not increased by cryopreservation in TK6 cells. There was inter-laboratory variation in levels of DNA strand breaks in THP-1 cells (SD = 3.7% Tail DNA) and TK6 reference sample cells (SD = 9.4% Tail DNA), whereas the intra-laboratory residual variation was substantially smaller (i.e. SD = 0.4%-2.2% Tail DNA in laboratories with the smallest and largest variation). In conclusion, the study shows that accumulation of DNA strand breaks in cryopreserved mononuclear blood cell lines is not a matter of concern.Certain authors have acknowledged funding as follows: statutory funding for INTC and IRH (M.W. and M.K.); Spanish Ministry of Science and Innovation MCIN/ AEI/10.13039/501100011033 (Grants PID2020- 113788RB-I00 and PID2020-114908 GA-I00), and Xunta de Galicia (Grant ED431B 2022/16) (V.V. and B.L.); Università degli Studi di Firenze fund RICATEN21 and RICATEN22 (L.G.).info:eu-repo/semantics/publishedVersio

Inter-laboratory variation in measurement of DNA damage by the alkaline comet assay in the hCOMET ring trial

The comet assay is a simple and versatile method for measurement of DNA damage in eukaryotic cells. More specifically, the assay detects DNA migration from agarose gel-embedded nucleoids, which depends on assay conditions and the level of DNA damage. Certain steps in the comet assay procedure have substantial impact on the magnitude of DNA migration (e.g. electric potential and time of electrophoresis). Inter-laboratory variation in DNA migration levels occurs because there is no agreement on optimal assay conditions or suitable assay controls. The purpose of the hCOMET ring trial was to test potassium bromate (KBrO3) as a positive control for the formamidopyrimidine DNA glycosylase (Fpg)-modified comet assay. To this end, participating laboratories used semi-standardized protocols for cell culture (i.e. cell culture, KBrO3 exposure, and cryopreservation of cells) and comet assay procedures, whereas the data acquisition was not standardized (i.e. staining of comets and image analysis). Segregation of the total variation into partial standard deviation (SD) in % Tail DNA units indicates the importance of cell culture procedures (SD = 10.9), comet assay procedures (SD = 12.3), staining (SD = 7.9) and image analysis (SD = 0.5) on the overall inter-laboratory variation of DNA migration (SD = 18.2). Future studies should assess sources of variation in each of these steps. On the positive side, the hCOMET ring trial demonstrates that KBrO3 is a robust positive control for the Fpg-modified comet assay. In conclusion, the hCOMET ring trial has demonstrated a high reproducibility of detecting genotoxic effects by the comet assay, but inter-laboratory variation of DNA migration levels is a concern.Certain authors have acknowledged funding as follows: statutory funding for INTC and IRH (Maria Wojewodzka and Marcin Kruszewski); Spanish Ministry of Science and Innovation (Ref.: PID2020-115348RB-I00) (Amaya Azqueta and Miguel Collia); Spanish Ministry of Science and Innovation MCIN/AEI/10.13039/501100011033 (Grants PID2020-113788RB-I00 and PID2020-114908 GA-I00), and Xunta de Galicia (ED431B 2022/16) (Vanessa Valdiglesias and Blanca Laffon); Universita degli Studi di Firenze Fund RICATEN21 and RICATEN22 (Lisa Giovannelli)