Jan Długosz University

About: Jan Długosz University is a education organization based out in Częstochowa, Poland. It is known for research contribution in the topics: Crystal structure & Luminescence. The organization has 749 authors who have published 2311 publications receiving 19395 citations. The organization is also known as: Higher Teacher Education School.

Proliferation of cells and expression of RARs, RXRs and HPV viral E6 and E7 proteins in cervical cancer cell lines after treatment with ATRA.

Abstract: All-trans retinoic acid (ATRA) is considered to be a potential chemotherapeutic drug due to its capability to regulate cell growth and differentiation. The effects of ATRA on the proliferation of cells and gene regulation are mediated by retinoid receptors (RAR and RXR), which belong to the nuclear receptor superfamily of ligand- inducible transcription factors. ATRA can act either as a growth inhibitor or growth promoter, according to the functional state of retinoic receptors. Thus, we have established the effect of ATRA on the proliferation of cervical cancer cells line HeLa and CaSki and expression of retinoids receptors as well as the viral HPV oncogenic proteins E6 and E7. ATRA had no effect on proliferation CaSki cells, but it stimulated the growth of HeLa cells, which depended on the incubation time and the concentration of ATRA in cell culture. The overexpression of RAR alpha in HeLa cells after the administration of 10(-7) mM ATRA was also observed 72 hours, and the decrease of CaSki by 60-90%. In the study of cervical cancer cell lines, the very low levels of other endogenous RAR and RXR receptors were observed. ATRA does not repress the expression of two viral oncoproteins E6 and E7 HPV16/18, which play a key role in carcinogenesis of the cervix. Our results support the suggestions that the cell response to vitamin A, and other retinoids in the diet, may depend on cell type, and that the cancer cells are differentially resistant to retinoids. Thus, despite the important biological functions of retinoids, the effects of retinoids in a supplementation in supra-physiological doses as well as their physiological action are difficult to define.

LiZn4 − x (x = 0.825) as a (3 + 1)-dimensional modulated derivative of hexagonal close packing

Abstract: The (3+1)-dimensional modulated structure of the LiZn4 - x (x = 0.825) binary compound has been determined in the superspace. The compound crystallizes in the orthorhombic superspace group Cmcm(α00)0s0 with a = 2.7680 (6), b = 4.7942 (6), c = 4.3864 (9) A, modulation wavevector: q ≃ 4/7a*. The structure is a derivative from the hexagonal close packing. The cubo-octahedron as a coordination polyhedron (c.n. = 12) is typical for all atoms. Bonding between atoms is explored by means of the TB-LMTO-ASA program package. The absence of strong interatomic interactions in LiZn4 - x is the main reason for the possible structure transformations.

Kinematics of the turning kick: measurements obtained in testing well-trained taekwon-do athletes

Abstract: Sherpa Romeo blue journal. Open access article. Creative Commons Attribution Non-commercial 4.0 License (CC BY-NC 4.0) applies.

Positron annihilation study of the free volume changes in thermally treated polymers based on acrylate oligomers

Abstract: Positron annihilation lifetime spectroscopy has been applied to the study of free volume properties in polymers based on the acrylate oligomers. The measurements have been made on samples heated to a temperature of 483 K. A differential scanning calorimeter was used for the study of the thermal properties. The longest lifetime, obtained via three-component analyses of the spectra, was associated with the pick-off annihilation of ortho-positronium trapped in the free volume. After the thermal treatment, changes in the ortho-positronium lifetimes and the relative intensity of the longest component were observed. These results are discussed on the basis of a free volume model.