ugosz University

Częstochowa, Poland

ugosz University

Częstochowa, Poland
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Miedzinski R.,ugosz University | Fuks-Janczarek I.,ugosz University | Kassab L.R.P.,São Paulo State Technological College | Bomfim F.A.,University of Sao Paulo
Materials Research Bulletin | Year: 2017

This paper reports the second- and third- order nonlinear properties of Er3+/Yb3+ -doped PbO-GeO2-Ga2O3 glasses with Au nanoparticles. The glasses were prepared by the melt-quenching technique, followed by annealing for the nucleation of gold nanoparticles. A 200 kV high-resolution transmission electron microscope (HR-TEM) was used to verify the presence of Au nanoparticles and estimate their sizes. The role of annealing on the possible variation of the third-order nonlinear electric susceptibility is studied in details following the possible changes in the Au nanoparticle concentration. Two-photon absorption (TPA) coefficient (β) and nonlinear refractive index (n2) was measured by the conventional Z-scan method at 532 nm wavelength. The highest values were obtained for the sample with gold nanoparticles annealed for 52 h. Second harmonic generation (SHG) measurements were also performed and showed low conversion efficiency. © 2017 Elsevier Ltd

Fuks-Janczarek I.,ugosz University | Miedzinski R.,ugosz University | Kassab L.R.P.,São Paulo State Technological College | Alves F.M.,São Paulo State Technological College
Materials Research Bulletin | Year: 2016

Studies of third-order nonlinear optical phenomena on Yb3+/Tm3+ co-doped PbO-GeO2 glasses containing different concentration of silicon nanoparticles are presented. The well-known melting-quenching technique was used for the production of the samples. Measurements were performed using conventional Z-scan, SHG and ESHG methods with Q-switched mode-locked ns scale Nd-YAG lasers, intensities in the 0.8-1.2 GW/cm2 power density range and repetition rate of 10 Hz. Maximum third-order susceptibilities and second harmonic generation were found for the sample prepared with 1 wt% of Si powder. © 2016 Elsevier Ltd. All rights reserved.

Fuks-Janczarek I.,ugosz University | Miedzinski R.,ugosz University | Brik M.G.,University of Tartu | Majchrowski A.,Military University of Technology | And 2 more authors.
Solid State Sciences | Year: 2014

The Z-scan measurements for the non-centrosymmetric optical crystals β-BaTeMo2O9 (BTMO) were performed. The corresponding experiments were carried out using the 5 ns pulses of the second harmonic of a nanosecond Nd:YAG laser at the 532 nm wavelength. It was shown that the studied crystals possess promising third-order optical susceptibilities, which allow to use the crystal as optical limiters. The comparison with other oxide materials is presented. To clarify the origin of the observed effect, the electronic and optical properties of BTMO were calculated using the density functional theory (DFT)-based method. The performed calculations of the electronic and optical properties revealed certain peculiar features that can be suitable for the nonlinear optical applications. The relation between the observed nonlinear optical features and the calculated band structure is emphasized. The values of the calculated band gap and refractive index for β-BaTeMo2O 9 are also reported. © 2013 Elsevier Masson SAS. All rights reserved.

Jagan Mohini G.,Andhra Loyala College | Sahaya Baskaran G.,Andhra Loyala College | Ravi Kumar V.,Acharya Nagarjuna University | Piasecki M.,ugosz University | Veeraiah N.,Acharya Nagarjuna University
Materials science & engineering. C, Materials for biological applications | Year: 2015

Soda lime silica borate glasses mixed with different concentrations of TiO2 are synthesized by the melt-quenching technique. As a part of study on bioactivity of these glasses, the samples were immersed in simulated body fluid (SBF) solution for prolonged times (~21 days) during which weight loss along with pH measurements is carried out at specific intervals of time. The XRD and SEM analyses of post-immersed samples confirm the formation of crystalline hydroxyapatite layer (HA) on the surface of the samples. To assess the role of TiO2 on the formation of HA layer and degradability of the samples the spectroscopic studies viz. optical absorption and IR spectral studies on post- and pre-immersed samples have been carried out. The analysis of the results of degradability together with spectroscopic studies as a function of TiO2 concentration indicated that about 6.0 mol% of TiO2 is the optimal concentration for achieving better bioactivity of these glasses. The presence of the maximal concentration octahedral titanium ions in this glass that facilitates the formation of HA layer is found to be the reason for such a higher bioactivity. Copyright © 2015 Elsevier B.V. All rights reserved.

Piasecki M.,ugosz University | Piasecki M.,Czestochowa University of Technology
Transactions of the Indian Ceramic Society | Year: 2012

Some effects induced by laser treatment in GeS2 glasses, glass-ceramics and selected chalcogenide crystals are presented. We show that thermal treatment of glasses or introducing controlled disorder in crystal lattice give the opportunity to make the desired changes in the optical and electrical properties of materials. Irradiation by CW and pulsed lasers can significantly change the absorbance and birefringence in the 400-800 nm spectral range. We have observed and measured changes of absorption and refractive index, and investigated relaxation process after switching off the irradiation. Chalcogenide crystals were promising for use in optically operated devices through their photoconductivity and efficient frequency doubling. Different possible mechanisms responsible for the effects are discussed. © 2012 Copyright The Indian Ceramic Society.

Xue B.,CNRS Chemistry Institute of Rennes | Nazabal V.,CNRS Chemistry Institute of Rennes | Piasecki M.,ugosz University | Calvez L.,CNRS Chemistry Institute of Rennes | And 4 more authors.
Materials Letters | Year: 2012

A transient effect induced by an irradiation treatment using a cw green (532 nm) laser or a microsecond pulsed CO 2 laser at 10.6 μm was observed on the absorbance and on the refractive refractive index in the visible spectral range. We have found modifications of absorption and refractive index in visible range which relax and disappear after the power cut of irradiation. Two main mechanisms participate in the observed photo-induced effects: the polarization of trapping states within the energy band-gap should be due to pure electronic contribution and/or related to the phonon sub-system manifesting through electron-phonon interactions. The relaxation of the photo-induced changes, after switching off the laser treatment, is also studied. © 2011 Elsevier B.V. All rights reserved.

Berdowski J.,ugosz University | Berdowska S.,Silesian University of Technology | Aubry F.,University of Lorraine
Archives of Metallurgy and Materials | Year: 2013

The purpose of this paper was to investigate the physical and mechanical properties of compressed expanded graphite CEG and their porous derivatives after impregnation, polymerization; and carbonization by the use of acoustic emission method (AE). The mechanical and structural characteristics of compressed expanded graphite and their three groups of porous composites after each technological process are presented and discussed. The measurements of acoustic emission parameters in these materials were carried out at wide range of frequency of the waves (0.1÷F2.5 MHz). The changes of two of parameters: - AE pulses counts rate and spectrum distribution of AE waves - are presented in this paper. The analysis of the respective parameters AE also gives possibility to determine the micro- and macro structural changes of materials at different levels of technological processes. Applications of these materials as catalysts with high specific surface make them very interesting subject of study. Also compressed expanded graphite composite membranes prepared from furfuryl alcohol polymers are promising for gas separation.

Wojciechowski A.,Czestochowa University of Technology | Kityk I.V.,Czestochowa University of Technology | Lakshminarayana G.,Nagoya Institute of Technology | Fuks-Janczarek I.,ugosz University | And 3 more authors.
Physica B: Condensed Matter | Year: 2010

The influence of irradiation by a cw 532 nm laser on the behavior of the absorption and optical second harmonic generation of triglicyne-zinc chloride crystal has been studied. Additional absorption bands correlate well with the time of the cw laser exposure. These lines occur at 260 nm, 305 nm, and, with small intensity, at 355 nm. The remaining part of the spectra shows substantially less changes. According to the performed quantum chemical simulations, one may expect that the observed dependences and the stability of the observed photoinduced changes are caused by formation of polarized electron-phonon states and the principal role should belong here to the electron-phonon anharmonicities, which cause the effects described by the non-polar third rank polar tensor like optical second harmonic generation. The increasing optical SHG signal shows a clear correlation with the behavior of the green laser-532 nm. It is important principal that for the blue laser-405 nm, the SHG effect is substantially less. This may reflect that the additional absorption maxima may be responsible for the non-linear optical effects. The effect demonstrates a slow time decay. © 2010 Elsevier B.V. All rights reserved.

Wojciechowski A.,Czestochowa University of Technology | Ozga K.,Czestochowa University of Technology | Reshak A.H.,University of South Bohemia | Reshak A.H.,University Malaysia Perlis | And 4 more authors.
Materials Letters | Year: 2010

An influence of the cw laser treatment at 660 nm (red), 532 nm (green) and 405 nm (blue) wavelengths on the absorption in l-alanine crystals was studied. We have established that increasing time of illumination for red laser wavelength leads to slight changes of absorption backgrounds without changes in the spectral features. The drastic changes are observed after illumination by green laser leading to occurrence of two clear and several less clear bands correlating well with increasing illumination time. Their intensities are only slightly dependent on time of optical treatment. The remaining part of the spectra demonstrates substantially less changes. Increasing optical SHG show clear correlation with the behavior of the red laser induced absorption. The effect demonstrates slow time decay. © 2010 Elsevier B.V.

News Article | December 14, 2016

Cancer treatment is still one of the most intractable challenge for medicine. There are several approaches to fight cancer, which include: surgery, radiation therapy, chemotherapy, immunotherapy, targeted therapy and hormone therapy. From all these treatment methods, chemotherapy seems to be the most widely used. Therefore, it is understandable that scientists are trying to discover new molecules which may be applied as effective chemotherapeutics. The researchers from Jan D?ugosz University in Cz?stochowa and Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences reviewed the most significant achievements in the area of cancer treatment, published in 2014/2015. This review describes newly discovered anticancer molecules interacting with DNA or affecting cancer cell cycles. New cancer treatment strategies, which increase efficiency of chemotherapy or radiotherapy and new chemotherapeutic delivery systems have also been mentioned in the review. Multiplicity of the described compounds proves that cancer battle is still in progress. We constantly learn something new about cancer cells and hopefully we are getting closer to find effective cancer treatment. We know that molecules can interact with cancer DNA by inhibiting its synthesis, transcription or duplication. Chemotherapeutics are also able to affect tumor cell cycle by suppressing itsproliferation and angiogenesis, and also promoting its apoptosis. However, developing effective cancer treatment is, still, a demanding task because the number of cancer cell-types known to researchers constantly increases. In spite of all these odds, we hope that along with the development of science, people will win the race with still incurable cancers. For more information about the article, please visit http://benthamscience. Reference: Turek, M.; (2016). New Hopes in Cancer Battle - A Review of New Molecules and Treatment Strategies Med. Chem., DOI: 10.2174/1573406412666160502153700

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