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Search Results: 1 - 10 of 167587 matches for " E. Krasicka-Cydzik "
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Tailoring of anodic surface layer properties on titanium and its implant alloys for biomedical purposes
E. Krasicka-Cydzik
Journal of Achievements in Materials and Manufacturing Engineering , 2010,
Abstract: and nanostructural titania and alloy component oxides. Evaluation of their properties for various biomedical applications in implantology and biosensing.Design/methodology/approach: Samples of titanium and its alloys were anodized in phosphoric acid solutions at different concentrations (0.5 ~ 4 M) with or without additions according to appropriate polarization regimes. Anodized samples were characterized by SED+EDS, electrochemical and impedance (EIS) tests and biocompability examination. Titanium and its alloys (Ti6Al4V and Ti6Al7Nb) samples were also used to form the nanostructural layer (nanotubes) by anodizing. The latter was used as a platform for glucose biosensing.Findings: Anodizing of titanium materials in phosphoric acid solutions allowed to obtain surface layers of various morphology and topography. They differ in porosity, thickness and chemical composition and according to their specific properties can be used in various biomedical applications. The development of gel-like layer and formation of nanotube layer was observed while anodizing in higher concentration of electrolyte or anodizing in the presence of fluorides. Both surface layers are much more bioactive than anodic barrier oxide layers on titanium. The primary tests to use nanostructured layer as platform for the third generation biosensors were promising.Practical implications: Use of medical implants covered with porous and nanostructural anodic layers tailored to particular biomedical purposes enables new practical applications in implantology and biosensing.Originality/value: Phosphate gel-like layer over surface oxide layer on titanium materials and nanostructural surface layer rich in both: phosphates and fluorides, are highly bioactive, which is the desirable property of implant materials.
Behavior of anodic layer in Ringer’s solution on Ti6Al4V ELI alloy after bending
E. Krasicka-Cydzik,A. Kierzkowska,I. Glazowska
Archives of Materials Science and Engineering , 2007,
Abstract: Purpose: Characterization of the electrochemical behavior of anodized implant rods made of the titanium alloy Ti6Al4V ELI after immersion in air-saturated Ringer’s solution was presented in the paper.Design/methodology/approach: The anodized and deformed by bending at angle 20o specimens (dia 6 mm) were characterized electrochemically in two zones: the max tensile (I) and the max. compressive stress (II). Impedance spectra (EIS) and corrosion potential measurements were performed on 1, 6, 10 and 16th day after immersion in Ringer`s solution.Findings: Bending caused an apparent decrease of the protective properties of the anodic layer, but the characteristic two-layer anodic film and the values of corrosion potentials were restored due to immersion in Ringer’s solution. The regions of the compressive stresses show much stronger tendency to regenerate surface properties.Research limitations/implications: The electrochemical tests in Ringer’s solution performed only in static conditions will be followed by fatigue tests in SBF.Practical implications: Results of the work are of great importance for surgical practice in the pre-operative stage of spinal surgery procedures. The explanation of the observed phenomena is proposed.Originality/value: Different stress zones formed on implant alloy during bending were described electrochemically. Results of studies evidenced that changes in the electrochemical behaviour in vitro in Ringer’s solution are advantageous with regard to the protective properties of the investigated alloy.
Effect of bending on anodized Ti6Al4V alloy: II. Behavior in vitro
E. Krasicka-Cydzik,A. Kierzkowska,I. Glazowska
Journal of Achievements in Materials and Manufacturing Engineering , 2006,
Abstract: Purpose: Evaluation of the influence of plastic deformation and characterization of the electrochemical behaviour of anodized implant rods made of the titanium alloy Ti6Al4V after immersion in air-saturated Ringer’s solution was presented in the paper.Design/methodology/approach: The specimens (dia 6 mm) were anodized and deformed by bending at angle 20o. The comparative characteristics of two zones: the max tensile (I) and the max. compressive stress (II) was based on the determination of electrochemical properties. Impedance spectra (EIS) and corrosion potential measurements were performed on 1, 6, 10 and 16th day after immersion in Ringer`s solution.Findings: Although bending caused an apparent decrease of the protective properties of the anodic layer, the characteristic two-layer anodic film and the values of corrosion potentials were restored due to immersion in Ringer’s solution. The regions of the compressive stresses show the much stronger tendency to restore.Research limitations/implications: The electrochemical tests in Ringer’s solution were performed only in static conditions. Fatigue tests in SBF are in progress.Practical implications: The explanation of the observed phenomena is proposed. Results of the work are of great importance for surgical practice in the pre-operative stage of spinal surgery procedures.Originality/value: Various stress zones formed on implant alloy during bending were described. The results of studies presented in the paper evidenced that changes noticed in the electrochemical behaviour in vitro in Ringer’s solution are advantageous with regard to the protective properties of the investigated alloy.
Effect of bending on anodized Ti6Al4V alloy: I. Surface layers characteristics
A. Kierzkowska,M. Malinowski,E. Krasicka-Cydzik
Journal of Achievements in Materials and Manufacturing Engineering , 2006,
Abstract: Purpose: The plastic deformation behaviour of the anodized binary titanium alloy Ti6Al4V was characterizedin mechanical and electrochemical tests.Design/methodology/approach: The effect of tensile and compressive stresses on properties of differentclinically relevant surfaces of the deformed by bending implant rods was investigated. The deformationbehaviour was characterized by FEM analysis. Relevant surfaces in tensile and compressive zones werecharacteristics by microhardness and roughness measurements, and electrochemical testing (Ecor, anodicpolarization, EIS) in oxygen-saturated Ringer’s solution.Findings: It was concluded that bending influenced mostly the properties of material in the tensile zone of thespecimen, whereas the properties of surface layer in the compressive zone and the properties of surface layer intensile zone after rebending are comparable and not so severe.Research limitations/implications: Studies were performed in static conditions, fatique studies are planned inthe future.Practical implications: Results are of great importance in for surgical practice in the in the evaluation of theinfluence of shaping process applied during pre-operative procedures on the performance of spinal implantsystems.Originality/value: In the paper a typical pre-operative procedure of shaping was applied to anodized titaniumimplants in order to evaluate its influence on the characteristics of the surface layer. Studies were focused onthe safety their application in vivo.
Electrochemical formation of bioactive surface layer on titanium
E. Krasicka-Cydzik,K. Kowalski,I. Glazowska
Journal of Achievements in Materials and Manufacturing Engineering , 2006,
Abstract: Purpose: Electrochemical oxidation method to form thin gel-like layer and activate titanium surface for calciumphosphate depositionDesign/methodology/approach: Titanium was anodised galvanostatically with low current density fromcathodic potential in 2 M H3PO4 solution up the steady state potential. This treatment produced two-layersurface film with thin (about 100 nm) gel-like phosphate film over the oxide layer with thickness of about 30nm on the titanium surface. The composition and chemistry of electrochemically treated titanium surfaces wereexamined by X-ray photoelectron spectroscopy (XPS). The effectiveness of the new treatment was examinedby comparing the behavior of treated and untreated titanium when used for biomimetic coating with theElectrochemical Impedance Spectroscopy (EIS) used for this purpose.Findings: A thick Ca–P coating was formed on the treated titanium after immersion in SBF solution and surfacemorphology was then examined using SEM equipped with EDS facilities.Practical implications: new electrochemical method of coating titanium and its implant alloys with bioactivesurface layer is more efficient and faster than the other in practical use.Originality/value: This study continues to support the further investigation of active phosphates for improvedorthopedic applications.
Effect of fluorides on bioactivity of titania nanotubes in SBF solution – by EIS studies
E. Krasicka-Cydzik,K. Bia?as-Heltowski,I. G?azowska,T. Klekiel
Archives of Materials Science and Engineering , 2011,
Abstract: Purpose: The influence of fluorides concentration in anodizing electrolyte on deposition of calcium phosphates Ca-O-P on titania nanotubes immersed in simulated body fluid (SBF) has been examined.Design/methodology/approach: The electrochemical impedance spectroscopy (EIS) was used to monitor the process of deposition of calcium phosphates on titanium foils covered with titania nanotubes formed by anodizing in 1 M H3PO4 with various amounts of fluorides ranging from 0.2 wt% to 0.4 wt%. The changes in impedance characteristics combined with results of SEM and EDS analyses were used to evaluate the bioactivity of nanotubes in SBF and find out the relation between the morphology of deposits and the concentration of fluorides in the anodizing electrolyte.Findings: The obtained results confirmed that titania nanotubes strongly favour the deposition of calcium phosphates (HAp) during the first 24 hours. However, the behavior of titania nanotubes formed in the electrolytes of various fluoride content differ afterwards when immersed longer in SBF solution. Particularly, contrary to other samples, the amount of deposits on nanotubes formed in 1 M H3PO4+0.30% wt. HF decreases significantly about 72 hours after immersing and these observations are recorded by both the SEM/EDS examination and XPS results. The corresponding changes in impedance parameters are noticed.Practical implications: Development of the method to cover titanium implant materials with nanoporous anodic layer, enriched in phosphates and fluorides- both ions highly supporting bioactivity, enables new applications in implantology and biosensing.Originality/value: Bioactivity is highly desirable property of implant materials. The phenomena observed during immersion in SBF solution by the Electrochemical Impedance Spectroscopy are related to the amount of fluorine in titania nanotubes. The explanation of this behavior and its consequence to bioactivity is proposed.
Architecture of Ambrosia psilostachya DC. Individuals in different habitats
Maciej Korczyński,Ewa Krasicka-Korczyńska
Acta Agrobotanica , 2011, DOI: 10.5586/aa.2011.053
Abstract: Ambrosia psilostachya is a plant of North American origin, well-domesticated in Poland. It covers ruderal habitats and is found in crops and in city green areas. The density of ragweed shoots in the researched areas ranged from 55 to 111 per m2. The production of biomass of this species relates to the production of synanthropic communities and city lawns. The factor limiting the population is cutting which affects mostly the number of shoots per patch, less considerably the state of a single individual. Habitats affected by mechanical factors are the biggest source of pollen causing allergies .
Nitrogen removal from wastewater and bacterial diversity in activated sludge at different COD/N ratios and dissolved oxygen concentrations
Magdalena Zieli&#,sk,Katarzyna Bernat,Agnieszka Cydzik-Kwiatkowsk,Joanna Sobolewska,Irena Wojnowska-Baryla,
Magdalena Zieli&#
,sk,Katarzyna Bernat,Agnieszka Cydzik-Kwiatkowsk,Joanna Sobolewsk,Irena Wojnowska-Baryla

环境科学学报(英文版) , 2012,
Abstract: The impact of the organic carbon to nitrogen ratio (chemical oxygen demand (COD)/N) in wastewater and dissolved oxygen (DO) concentration on carbon and nitrogen removal efficiency, and total bacteria and ammonia-oxidizing bacteria (AOB) communities in activated sludge in constantly aerated sequencing batch reactors (SBRs) was determined. At DO of 0.5 and 1.5 mg O2/L during the aeration phase, the efficiency of ammonia oxidation exceeded 90%, with nitrates as the main product. Nitrification and denitrification achieved under the same operating conditions suggested the simultaneous course of these processes. The most effective nitrogen elimination (above 50%) was obtained at the COD/N ratio of 6.8 and DO of 0.5 mg O2/L. Total bacterial diversity was similar in all experimental series, however, for both COD/N ratios of 6.8 and 0.7, higher values were observed at DO of 0.5 mg O2/L. The diversity and abundance of AOB were higher in the reactors with the COD/N ratio of 0.7 in comparison with the reactors with the COD/N of 6.8. For both COD/N ratios applied, the AOB population was not affected by oxygen concentration. Amplicons with sequences indicating membership of the genus Nitrosospira were the determinants of variable technological conditions.
Cluster Model of Formation of Subnuclear and Subatomic Objects  [PDF]
E. E. Lin
Journal of Modern Physics (JMP) , 2014, DOI: 10.4236/jmp.2014.53018
Abstract:

The paper describes the development results on one-dimensional (1D) asymptotic model of the formation kinetics for the objects (clusters) of subnuclear (quark) and subatomic (nuclear) matters. A concept of the objects distribution density wave φ(a, t) in space of sizes a lies in the basis for analytical description of the processes under consideration. The proposed formalism makes it possible to describe in an adequate way the final outcomes of the well-known catastrophic phenomena in the world of elementary particles. Mass characteristics of different processes of approach to equilibrium in nuclear reactions are calculated.

The Gene as Natural Nanomaterial for Treatment of Diseases  [PDF]
E. E. Escultura
Open Journal of Biophysics (OJBIPHY) , 2017, DOI: 10.4236/ojbiphy.2017.71003
Abstract: As an application of the grand unified theory (GUT) to medicine, this paper introduces two natural nanomaterials—the gene and electromagnetic wave. They are involved in the proposed treatment of genetic and infectious diseases. It introduces the superstring as the fundamental building block of matter and the basic constituent of dark matter, one of the two fundamental states of matter. It also introduces the primum, unit of visible or ordinary matter, the other fundamental state of matter. They are convertible to each other by the action of basic cosmic or electromagnetic waves. Eleven biological laws define biology as a biological and physical theory. The gene is the primitive ingredient of living things and, therefore, the beginning of biological life and the virus the simplest living thing. Treatment ranges from genetic modification and alteration to remove undesirable symptom through genetic sterilization to stop the spread of the disease and outright destruction of the disease. Genetic sterilization and outright destruction apply also to infectious diseases. The paper concludes with a blueprint for research and development of appropriate technologies for the treatment.
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