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1
Content available Rozważania semi-analityczne nt. dorobku naukowego Profesora Czochralskiego wraz z pytaniem o jego zakres?
Gadomski A.
Chemik
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2014
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Vol. 68, nr 5
500--504
EN
In this semianalytic study, a question has been raised, and then answered, as to what extent Jan Czochralski, a renown Polish chemist, crystallographer and metallurgist, or even material (viz metal) scientist, etc., should belong, in terms of his achievements, to (physicochemical) metallurgy or ought to be recognized rather as a chemist, working with metals and their “doped derivatives”. The bare ground for answering the question consists of the fact that he did his research quite unseparably within physicochemical and/or mechanochemical (as a specific important subject) metallurgy of quite complex as well as very practical systems that he was able to address thoroughly by his investigations.
2
Content available remote The role of lamellate phospholipid bilayers in lubrication of joints
Pawlak Z., Urbaniak W., Gadomski A., Yusuf K.Q., Afara I.O., Oloyede A.
Acta of Bioengineering and Biomechanics
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2012
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Vol. 14, no. 4
101-106
EN
This study aims to determine the effect of progressive loss of the surface active phospholipids on the characteristics, and hence tribological function of articular cartilage. In accordance to Hill's hypothesis, 3-7 lipid bilayers at pH 7.4 operate as the solid lubricant in the cartilage-cartilage interface during physiological function. These bilayers are known to be depleted during cartilage degeneration. This study models this loss of phospholipid bilayers, studying experimentally both wet and dry cartilage surfaces, measuring surface wettability, and friction coefficient under a constant stress of 1.2 MPa. The results demonstrate that the friction coefficient increases gradually with loss of the phospholipid bilayers, and gains in value with decrease in wettability.
3
Content available remote A biochemical model for characterising the surface-active phospolipid bilayer of articular cartilage relative to acid-base equilibrium
Pawlak Z., Kotynska J., Figaszewski Z., Gadomski A., Gudaniec A., Oloyede A.
Archives of Materials Science and Engineering
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2008
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Vol. 29, nr 1
24-29
EN
Purpose: This paper, addresses the question of how changes in acid - base equilibrium influence change in the charge density of the phospholipid bilayer on articular cartilage surfaces during lubrication. Design/methodology/approach: Liposomes have been used to mimic biological phospholipid membranes on articular cartilage surface where proteins are bounded, ions are transported, energy is transducted, and cellular processes take place. The charge density of the membrane was determined as a function of pH and electrolyte concentration from the microelectrophoretic method. Liposome membrane was prepared as an aqueous solution of NaCl under various pH conditions. Microelectrophoresis was used to examine the local acid-base equilibrium of the electrolytes with the membrane surface, which can be considered to model the phospholipids interface in articular cartilage. Findings: The adsorbed ions (H+, OH-, Na+, Cl-) which are present in the electrically charged solutions of liposome membrane comprising phosphatidycholine (PC), were found to exhibit pH-responsive quasi-periodic behavior. Research limitations/implications: We have established that the acid-base dissociation behavior in phospholipid bilayers of articular cartilage is a key to understanding biolubrication processes. For example,previous investigators found that the formation of the multilayer of polyisopeptide/hyaluronic acid depends on surface properties such as film thickness, surface friction, surface wetability; wetness and swelling behavior. Future work should consider the adsorption of polyelectrolyte ions, e.g., the glycoprotein lubricin and hyaluronan, on the liposome membrane surface in the presence of H+ and OH- ions. Originality/value: A novel model of the joints’ phospholipid bilayers has been created using liposome membrane This model can be applied in the investigation of polyelectrolyte ions such as lubricin, in articular cartilage. We have demonstrated that the acid-base processes on charged surfaces is a key mechanism in facilitating lubrication in human joints.
4
Content available remote Pierre-Gilles de Gennes (1932-2007)
Gadomski A.
Postępy Fizyki
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2007
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T. 58, z. 6
279-281
5
Content available remote Impact of the charge density of phospholipid bilayers on lubrication of articular cartilage surfaces
Pawlak Z., Kotynska J., Figaszewski Z. A., Oloyede A., Gadomski A., Gudaniec A.
Journal of Achievements in Materials and Manufacturing Engineering
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2007
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Vol. 23, nr 1
47-50
EN
Purpose: We attempt to answer the question how some changes in acid - base equilibrium have an impact on the charge density of a phospholipid bilayer formed during lubrication occurring at articular cartilage surfaces. Design/methodology/approach: Liposomes have been used to mimic biological phospholipid membranes on articular cartilage surface where proteins are bounded, ions are transported, energy is transducted, and cellular processes are taking place. The charge density of the membrane was determined as a function of pH and electrolyte concentration from the microelectrophoretic method. Liposome membrane has been prepared as an aqueous solution of NaCl under various pH conditions. Microelectrophoresis was used to examine the local acid-base equilibrium of the electrolytes with the membrane surface, which can be considered to be an interface of phospholipids in articular cartilage. Findings: The effects of the adsorption of ions (H+, OH- ; Na+, CI-), which are present in solution upon electric charge of the liposome membrane assembled of phosphatidycholine (PC), have also been found to exhibit pH-responsive (quasi-periodic) behavior. Research limitations/implications: We hypothesized that the acid-base dissociation behavior in phospholipid bilayers of articular cartilage is a key to understanding biolubrication processes. For example, similar previous investigators found that the behavior of a multilayer made of polyisopeptide/hyaluronic acid depends on some of the surface properties such as film thickness, surface friction, surface wetness and swelling conditions. Future work should consider the adsorption of polyelectrolyte ions, e.g., the glycoprotein lubricin and hyaluronan, at the liposome membrane surface involved, assumed that besides the H+ and OH- ions, the polyelectolyte ions were also engaged. Originality/value: This liposome membrane is a model for phospholipid bilayers and will be applied for the investigation of polyelectrolyte ions, e.g. lubricin, in articular cartilage conditions. We demonstrate that knowledge on the acid-base processes on charged surface is the key to understanding phenomena occurring at interfaces in human joints lubrication, thus pointing to the biolubrication as a charged interface-controlled process.
6
Content available remote Formation of soft material in terms of a coupled matter migration-and-relaxation picture: a synchronous mode
Gadomski A., Dressler M., Santamaría-Holek I., Rubi J. M.
Materials Science Poland
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2006
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Vol. 24, No. 4
935--949
EN
This study is devoted to draw a mesoscopic nonequilibrium thermodynamics (mnet)-based description of the model soft material, such as that made of clusters of amphiphilic molecules or biopolymer surfactants. The description offered also enters the region of nonlinear viscoelastic behaviour of soft-matter agglomerates, both in a fluctuation-driven (quantitatively, being realized in an synchronous mode) and some flow-driven (mostly, qualitatively) regime. A special emphasis is placed on a novel concept, termed the emergent (power-law) behaviour, which tries to effectively combine data available about specific soft-matter (complex) systems that under variety of physicochemical conditions often manifest a certain interesting mesoscopic properties
7
Content available remote Od metody wyznaczania szybkości krystalizacji metali do nowoczesnej technologii otrzymywania kryształów półprzewodnikowych i białkowych
Siódmiak J., Gadomski A.
Chemik
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2005
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Vol. 58, nr 10
535-538
PL
W pracy przedstawiono krótki zarys historyczny najważniejszych, zmieniających się w czasie metod otrzymywania kryształów i badania ich własności. Przegląd rozpoczęto od metody wyznaczania szybkości krystalizacji metali, znanej jako metoda CZ, od nazwiska jej odkrywcy Jana Czochralskiego. Przy okazji, niejako, przypomniano życiorys i najważniejsze dokonania tego wybitnego, urodzonego dokładnie 120 lat temu Polaka rodem z Pałuk (z Kcyni), ważnego historycznie regionu etniczno-kulturowego, leżącego pomiędzy Bydgoszczą, Inowrocławiem a Poznaniem. Przegląd kontynuowano omawiając podstawowe cechy nowoczesnej technologii otrzymywania kryształów półprzewodnikowych, a zakończono podkreślając wielką rolę dla rozwoju technologii przyszłości eksperymentów prowadzących do właściwego otrzymywania kryształów białkowych - pod-stawowego, tzw. miękkiego materiału eksperymentalnego, służącego do badania krystalograficznego struktur pojedynczych łańcuchów białkowych.
EN
In this work, a brief historical survey of over-time-changing methods of growing crystals, and examining their properties, has been presented. The survey has been started with a method of determination of the crystallization speed of metals, known as the CZ method, termed after the name of its inventor, Jan Czochralski. Benefiting somehow from the right-now-emerging opportunity, the biography as well as the main achievements of this outstanding Pole, born exactly 120 years ago in the Pałuki-Region (in Kcynia), an important ethnic-and-cultural Polish region, somewhere between Bydgoszcz and Inowrocław, and Poznań, has been recollected. The survey has been continued by discussing basic properties of modern technology of growing semiconductor crystals, and finished by emphasizing an immense role of appropriately growing protein crystals - a basic experimental soft material, serving for crystallographic examination of single protein chains.
8
Content available remote Model multilineal pattern formation : a computer experiment
Gadomski A., Cyrankiewicz M.
Computational Methods in Science and Technology
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2001
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Vol. 7, nr 2
75-90
EN
Multilineal pattern formation in the square lattice is studied. It turns out that lognormality both in space (size) and time appears to be a main signature thereof. A diffusive character of the emerging patterns has been emphasized, and some elucidation, supporting an understanding of the model phenomenon in question is provided. Excursions towards dynamics of the multiline as well as a relation to known kinetic or dynamic models have been offered as well.
9
Content available remote Teoria skalowania i układy nieuporządkowane [Ze zjazdów i konferencji]
Gadomski A.
Postępy Fizyki
|
2000
|
T. 51, z. 6
321-323
PL
W dniach 13-14 kwietnia 2000 r. w auli Langevina Ecole Superieure de Physique et Chimie Industrielles w Paryżu odbyło się Międzynarodowe Spotkanie Naukowe (International Workshop on Scaling and Disordered Systems) poświęcone teorii skalowania i jej zastosowaniom w układach nieuporządkowanych, tj. ciągle żywo rozwijającej się dziedzinie z pogranicza fizyki statystycznej i fizyki materii skondensowanej oraz innych dyscyplin naukowej aktywności fizyków, jak np. kosmologia, chemia i biologia, genetyka, a także ekonomia i polityka.
10
Content available remote Statistical Physics Applied to Practical Problems [Ze zjazdów i konferencji]
Gadomski A.
Postępy Fizyki
|
2000
|
T. 51, z. 2
98-99
PL
W dniach 19-22 maja 1999 r. na Politechnice w Budapeszcie odbyło się pod auspicjami Sekcji ds. Nauki NATO Naukowe Spotkanie Robocze (Advanced Research Workshop) poświęcone zastosowaniu metod i aparatu teoretycznego fizyki statystycznej do rozwiązywania praktycznych problemów w intensywnie rozwijających się w końcu XX w. dyscyplinach, jak np.: biologia i medycyna, ekologia, geologia, informatyka, technologia chemiczna i elektronowa, jak również w bardziej "egzotycznych" w pojęciu zastosowań fizyki działach, jak ekonomia, finanse czy też nauki społeczno-polityczne.
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