Wyniki wyszukiwania - Biblioteka Nauki

1

Clareon® – nowa generacja implantów wewnątrzgałkowych w systemie preloadowanym AutonoMe

100%

Kołodziejczyk W. , Jadowska E. , Kałużny B.

OphthaTherapy

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2018

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tom 5

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nr 3

143-148

EN

Innovation in the construction of artificial intraocular lenses has a major impact on the patient’s life comfort after cataract phacoemulsification surgery. In the times of intensive development of cataract surgery, the operator has the choice of the best implant option and the right treatment procedure. Lens production technology is a large area of research and a challenge for many manufacturers in terms of new biomaterials as well as their physical, mechanical and optical properties.

PL

Innowacyjność konstrukcji sztucznych soczewek wewnątrzgałkowych znacząco wpływa na komfort życia pacjenta po zabiegu fakoemulsyfikacji zaćmy. W czasach intensywnego rozwoju chirurgii zaćmy operator ma wybór najlepszej opcji implantu i odpowiedniej procedury leczenia. Technologia produkcji soczewek jest obszernym obszarem badań i stanowi wyzwanie dla wielu producentów zarówno pod względem nowych biomateriałów, jak i ich właściwości fizycznych, mechanicznych oraz optycznych.

2

Badania przedkliniczne usieciowanej hydroksyetylocelulozy - materiału implantacyjnego w stomatologii

88%

Wierucka-Młynarczyk B. , Ilewicz L. , Książek-Bąk H. , Bulek-Juranek G. , Łapkowski M. , Sabat D. , Turczyn R.

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1999

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tom z. 140

323-326

PL

Przedstawiono wyniki dwóch testów przedklinicznych. Test hemolityczny wykazał brak toksyczności usieciowanej hydroksyetylocelulozy. Test alergiczny na skórze świnek morskich wykazał całkowitą neutralność tego polimeru w stosunku do ich organizmu, co potwierdzono badaniami histopatologicznymi.

EN

The aim of this study was to present results of two preclinical examinations: haemolytic test and allergic test. The haemolytic test showed lack of hydroxyethylcellulose toxicity. Allergic test performed on the skin of guinea pigs revealed that polymer was completely neutral to their organism which was also confirmed in histopathological examination.

3

Potentiodynamic studies of stainless steel wire for endourology

75%

Przondziono J. , Walke W.

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2009

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tom Vol. 35, nr 1

21-28

EN

Purpose: The purpose of the study is to evaluate resistance to electrochemical corrosion of wire made of Cr-Ni stainless steel, designed for use in endourological treatment. The influence of strain formed in the process of drawing and methods of wire surface preparation to corrosive resistance in artificial urine solution were analysed. Design/methodology/approach: Wire corrosion tests were carried out in the solution of artificial urine with the use of the system for electrochemical tests VoltaLab ®PGP201. Resistance to electrochemical corrosion was evaluated on the ground of recorded curves of anodic polarization by means of potentiodynamic method. Mechanical properties of wire were tested by means of static uniaxial tension test. Findings: Potentiodynamic tests carried out in artificial urine enabled to determine how the resistance to pitting corrosion of wire changes, depending on strain formed in the drawing process as well as on the method of wire surface preparation. Deterioration of corrosive properties of wire along with the increase in the formed strain hardening was observed. Research limitations/implications: The obtained test results proved the suitability of the applied research methodology for evaluation of electrochemical corrosion resistance of wire made of stainless steel designed for use in endourology. Practical implications: Test results are of significant utilitarian value because they can determine the relation between pitting corrosion resistance and the volume of strain formed in the wire drawing process, and consequently their mechanical properties. Originality/value: The analysis of the results of electrochemical corrosion resistance tests showed positive impact of wire surface treatment by means of electrolytic polishing and chemical passivation method on improvement of its corrosive properties. It must be emphasised that despite the increase in corrosion resistance, obtained thanks to surface treatment, it is necessary to use protective coating on wire used in urology.

4

Effort changes of lower complete denture material caused by relining

75%

Żmudzki J. , Chladek W. , Krukowska J.

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2008

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tom Vol. 31, nr 2

79-82

EN

Purpose: Influence of dentures relining on saddles material effort in case of bone foundation not affected by any atrophic changes has been examined. Design/methodology/approach: Stresses levels in material of denture saddles bearing structure have been determined for any cases where alveolar ridges of mandible are well preserved. This research has been carried out in simulated conditions of biting loads, by means of a FEM. Compared were not-relined vs. relined saddles for two variants of bottom denture saddles margins, i.e. ended smoothly and with an extension that increases the amount of material of the bearing structure. Analyzed was also the influence on deformability of relining layers. Findings: Equivalent Huber-Misses stresses on a good saddles surface in case of a not-relined denture have slightly exceeded the level of 2 MPa, whereas in case of a relined denture with a soft margin they have reached 4 MPa; and for variant of relined denture with extended margin they reached a level of 14 MPa. Modulus of elasticity of the relining has not influenced significantly the effort of saddles material. Research limitations/implications: Assumed were vertical loading forces of 100 N simplified denture geometry without separating any complex shapes of artificial teeth. Practical implications: Increase of the bearing surface of relined saddles by means of extended margins results in stress concentration. Hence, attempts should be made to form the margins and teeth profiles changes at their base smoothly. All micro damages in endangered areas of saddles’ margins should be removed. Originality/value: Relining of low dentures’ saddles in a well preserved bone foundation does not directly result in excedance of allowable stress levels for prosthetic acrylic resins. Hence, the causes of failures should be sought in the impact of geometrical notches, or potentially existing damages that initiate degradation processes.

5

Loading of overdenture attachments under simulated biting forces

75%

Żmudzki J. , Chladek W. , Krukowska J.

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2008

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tom Vol. 32, nr 1

33-36

EN

Purpose: The basis for effectiveness evaluation of over-denture attachments is the determination of loads on supports, and denture mobility. In cases of denture stabilized on two prosthetic supports, for most of the attachments constructions that are available on the market, the margin of dentures mobility is limited to rotation around axes of the attachments. Design/methodology/approach: Determining attachments loadings during bearing of biting forces that accompany chewing processes was carried out by means of Finite Element Method model analysis. A three-dimensional model of a denture supported on mucous membrane and joint supports assumes to be fixed in places of denture anchoring to implants. This model was loaded on one side with unilateral oblique 100 N force at molars zone. Findings: Maximum loading at pillar accompanies biting forces acting in a lateral direction toward buccal side. Research limitations/implications: Researches were carried out exclusively for attachments not showing any resilience in any direction, without any rotational constrains. Hence, in further researches, at the first place, determined should be the influence of the vertical resiliency used in some of the commercial attachments on loads bearing. Practical implications: Appropriate determining of loadings levels on over-denture attachments, requires necessarily that the oblique biting forces will be taken into account. In case of an assumption of only vertically oriented biting forces, there is a significant underestimation of the most dangerous horizontal loadings of prosthetic supports. Originality/value: Presented displacements of denture and pillars loading as vertical and horizontal reactions causing pillar bending and leverage at the bone, constitute a starting point for evaluation of denture’s behavior and strength estimation of analyzed types of attachments for implants and the surrounding bone.

6

Mikrostruktura i skład fazowy kompozytów HAp+YSZ

75%

Dudek A.

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2008

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tom R. 8, nr 3

258-261

PL

W ostatnich latach nastąpił wyraźny postęp w rozwoju materiałów o specyficznych własnościach stosowanych w medycynie. Obecnie najbardziej perspektywicznym materiałem konstrukcyjnym są dwufazowe kompozyty HAp+ZrO2, które zostały wytworzone w ramach niniejszych badań. Kompozyty otrzymano w wyniku prasowania jednoosiowego dwóch proszków ceramicznych (HAp+YSZ), które następne spiekano w temperaturze 1300° C przez dwie godziny. Celem przeprowadzonych badań było określenie stabilności termicznej hydroksyapatytu i kompozytów HAp+YSZ oraz zbadanie wpływu dodatku YSZ (8% wag. Y2O3 stabilizujący ZrO2) na skład fazowy wytwarzanych kompozytów po przeprowadzeniu procesu spiekania. Hydroksyapatyt powyżej temperatury 900° C ulega degradacji, tworząc z ZrO2 liczne fazy, co nie zostało potwierdzone badaniami własnymi. Badania składu fazowego przeprowadzono za pomocą dyfraktometru rentgenowskiego Seifert 3003 T-T.

EN

Last years have seen a remarkable progress in development of materials with special properties used for the medicine. In particular, it encompasses a group of materials used for implants. Use of bioceramics materials as coatings for implants introduced into human body, due to their biocompatibility with human body enables overcoming immunological barriers. One of the solutions for improvement of poor properties (low mechanical strength and fracture toughness) of HAp is addition of zirconium oxide, which is characterized by higher biological tolerance and improved mechanical properties. Hydroxyapatite (HAp) and zirconia (ZrO2) are well-known and valuable implant materials. Preparation of two-phase HAp-ZrO2 composite material gives rise to some questions, which have not been fully clarified. The investigations involved preparation of composites through single-axial compaction of two ceramic powders (HAp+YSZ) and their sintering at the temperature of 1300° C for two hours. The aim of the investigations was to determine thermal stability of hydroxyapatite and HAp+YSZ and impact of addition of YSZ (8 wt. % Y2O3 stabilizing ZrO2) on phase composition of the prepared composites after the process of sintering. Nearly 900 ° hydroxyapatite starts to decompose by evaporating water and forming partially or completely dehydrated oxyhydroxyapatite. Particular attention is paid to the presence of phases after sintering process in HAp+ZrO2 composites. Investigations of phase composition have been carried out by means of Seifert 3003 T-T X-ray diffractometry.

7

20 lat doświadczeń z soczewką AcrySof® – jej wpływ na chirurgię zaćmy

75%

Jadowska E.

OphthaTherapy

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2015

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tom 2

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nr 3

213-222

EN

Unfortunately, there is no such thing as an organic replacement lens to be implanted after cataract surgery. That is why intraocular lens (IOL) must work with the eye’s natural physiology not only to mimic the biological functions of the crystalline lens, but also to maximize patient outcomes. While preparing a patient for surgery, we should take into account some factors which can determine the outcomes, such as: the IOL design, which will ensure stability and predictable refractive effect, a high biocompatibility with the tissues of the eye, and the protective effect to the eye. Properly selected lens can ensure restoration of functional vision, image quality, the best possible contrast or the reduction of spherical aberration, which all testify to the cataract surgery success.

PL

Niestety, nie istnieje naturalna soczewka, którą można wszczepić po zabiegu chirurgicznym zaćmy. Dlatego tak ważne jest, żeby sztuczna soczewka wewnątrzgałkowa działała zgodnie z naturalną fizjologią ludzkiego oka, nie tylko naśladując funkcje biologiczne, ale także zapewniając maksymalizację korzyści dla pacjenta. Zakładając, że soczewka wszczepiana jest dożywotnio, w ramach przygotowania pacjenta do operacji powinniśmy wziąć pod uwagę jej konstrukcję, która zapewni stabilność i przewidywalny efekt refrakcyjny, wysoką biokompatybilność z tkankami oka oraz działanie ochronne dla oka. Przywrócenie widzenia funkcjonalnego, jakości obrazu, jego jak najlepszego kontrastu, redukcja aberracji sferycznych pp. to sukces, jaki można osiągnąćdzięki odpowiednio dobranej soczewce.

8

FEM analysis of compression screws used for small bone treatment

75%

Kajzer W. , Kajzer A. , Marciniak J.

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2009

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tom Vol. 33, nr 2

189-196

EN

Purpose: The paper presents results of numerical analysis in metatarsal bone „I” - compression screws system. The aim of the work was determined stresses, strain and displacement in the inserted screws. Design/methodology/approach: Metatarsal bone „I” was selected to researches. The analysis was carried out on the metatarsal bone „I” - compression screws system. The influence of the loads and displacements on the bone - screws system on the results of numerical analyses was analyzed. In order to carry out calculations, 2 models of diverse mechanical properties of screw - Ti-6Al-4V alloy - model 1, stainless steel (Cr-Ni-Mo) - model 2 and two load steps were selected. Findings: The analyses showed the difference in displacements, strains and stresses depending on the selected mechanical properties screws and the way of loads. Research limitations/implications: The limitations were connected with simplification of numerical model of femur as well as with the selected boundary conditions. Two difference way of loads metatarsal bone „I” - compression screws system: 1_force F = 500 N, 2_ displacement l = 1 mm were applied. Practical implications: The obtained results can be useful in clinical practice. They can be applied in selection of stabilization methods or rehabilitation as well as in describing the biomechanical conditions connected with type of bone fracture obtained from medical imaging. Originality/value: Stress-strain-displacement characteristics of metatarsal bone „I” - compression screws system, obtained from the numerical analysis were presented in the work.

9

Nanokompozyty polimerowe do zastosowań medycznych

75%

Stodolak E. , Frączek-Szczypta A. , Błażewicz M.

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2010

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tom R. 10, nr 4

322-327

PL

Praca obejmuje badania nad biozgodnymi polimerami modyfikowanymi nanocząstkami ceramicznymi. Przedmiotem badań były nanokompozyty polimerowe, wytworzone z trzech różnych polimerów: polimeru biostabilnego (polisulfon - PSU), polimeru resorbowalnego (poli(L/DL)laktyd - PL(L/DL)A) oraz polimeru pochodzenia naturalnego (chitozan - CS). Jako modyfikatory zastosowano nanometryczne cząstki ceramiczne: montmorylonit (MMT), krzemionkę (SiO2) oraz nanorurki węglowe (CNT). Materiały nanokompozytowe zostały scharakteryzowane pod względem parametrów biologicznych i mechanicznych. Wyniki badań wskazują, że modyfikacja wszystkich trzech grup polimerów, przy zastosowaniu nanocząstek ceramicznych, to skuteczna droga do otrzymywania biozgodnych, bioaktywnych tworzyw, posiadających dodatkowo znacznie lepsze parametry mechaniczne w porównaniu z czystymi polimerami.

EN

Nanotechnology generally bases on modification of materials' behaviour. One of the first real products of nanotechnology is polymer nanocomposites, which are a combination of polymer matrix and nanoparticles (so called nanofillers) that have at least one dimension in a nanometric range. The nanofillers such as nanopowders, nanofibers, or nanotubes modify the polymer matrix on a molecular level. Properties of such materials depend both, on the matrix, and the nanoparticles. These materials may exhibit enhanced mechanical (tensile strength, stiffness, toughness), gas barrier, thermal expansion, thermal conductivity, ablation resistance, optical properties, chemical properties, electronic and magnetic properties. Polymer nanocomposites is a promising class of hybrid materials derived from both synthetic and natural polymers and inorganic/organic nanoparticles. The introduction of nanoparticles into a polymer matrix ensures significant improvement of the material's properties. Polymer nanocomposites are of immense interest of such biomedical technologies as; tissue engineering, bone replacement, dental applications and controlled drug delivery. Current opportunities for application of polymer nanocomposites in biomedical applications arise from their tailored bioactivity, biodegrabilty, and mechanical properties. Interaction between nanofillers and a polymer matrix enables them to act as molecular bridges in the polymer structure. High adhesion of nanoparticles to the polymer matrix results in the enhanced strength and Young's modulus of the nanocomposites comparing to conventional composites. The paper presents results of our investigations on three kinds of nanocomposites basing on biocompatible polymer matrices and nanoparticles such as; MMT, SiO2 and CNTs which constitute temporary replacing materials in a missing bone tissue. Such material should be biocompatible, osteoinductive, osteoconductive and porous as well as mechanically compatible with the bone tissue. The results of biological investigations provided evidence of good adhesion, proliferation and morphology of osteoblastic cells on the surface of each polymer nanocomposites. The ability of the polymer nanocomposite to cell attachment, spreading and growth in in vitro conditions, combined with the good mechanical properties suggest potential use of these material as biomedical devices, particularly in the area of regenerative medicine. Values of Young's modulus increase in all nanocomposites, and their tensile strength depends on dispersion of the nanoparticles in the polymer matrix, and in most cases decrease because of agglomeration of the nanoparticles. Polymer nanocomposite containing bioactive nanoprticles shows osteoinductive properties. Treatment of the nanocomposite samples in the simulated body fluid (SBF) induced some changes on the surface of the material containing bioactive ceramic nanoparticles. The results of the tests with SBF show that the material is able to produce apatite structure on its surface.

10

Analiza matematyczna skurczu kompozytów HA+ZrO2

75%

Dudek A.

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2009

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tom R. 9, nr 1

58-61

PL

W obecnych czasach kładzie się znaczny nacisk na poszukiwanie materiałów kościozastępczych, które pozwolą na wypełnianie powstałych z różnych przyczyn ubytków kości. Materiał, z którego wykonuje się implanty, nie może być szkodliwy dla organizmu człowieka, to znaczy: rakotwórczy, toksyczny, radioaktywny, oraz musi być odporny na korozję (w zależności od środowiska, w którym "pracuje"), musi być zgodny biologicznie (wykazujący zgodność tkankową, niewywołujący odczynów alergicznych), dobrze tolerowany przez tkanki żywe. W aspekcie powszechnego zastosowania w medycynie (stomatologii, chirurgii szczękowo-twarzowej, ortopedii i otolaryngologii) zarówno hydroksyapatytu, jak i kompozytów na bazie HA (z dodatkiem fazy ZrO2), bardzo ważne jest dokładne określenie zawartości procentowej dodatku fazy ZrO2 w mieszaninie, zapewniającej utrzymanie niezmiennych lub z góry oczekiwanych wymiarów implantu czy powłoki po procesie spiekania. W ramach badań wykonano kompozyty w wyniku prasowania jednoosiowego dwóch proszków ceramicznych HA+ZrO2, które następnie spiekano w temperaturze 1300°C przez dwie godziny. Celem badań było wykonanie opisu matematycznego pozwalającego oszacować skurcz objętościowy spieków HA+ZrO2 po przeprowadzonym procesie spiekania. Mając na celu uzyskanie uogólnionych zależności pomiędzy zawartością fazy ZrO2 a skurczem uzyskanych spieków, wykorzystano pojęcia regresji i korelacji. Dla uzyskanych punktów eksperymentalnych dopasowano, metodą najmniejszych kwadratów, równania regresji liniowej, obliczono współczynnik korelacji.

EN

Calcium hydroxyapatite is the main mineral component of bones, with the size of its crystals of 4-50 nm. Hydroxyapatite constitutes a kind of 'warehouse' for storage of calcium (99%) and phosphorus (85%), while its crystals account for 77% of organic stroma the bones are made of. Nowadays doctors, in their practice, often come across the problem of bone defects while bone graft is found to be a standard procedure. Nowadays, great emphasis is put on searching for new bone-replacing materials which would allow for replacement of bone defects that appear for a variety of reasons. Materials for implants must not be hazardous for human body, i.e. carcinogenic, toxic or radioactive, they have to be resistant to corrosion (depending on the environment they work within), biocompatible (the materials which show tissue compatibility and do not cause allergic reactions), well tolerated by living tissues. It is important, from the standpoint of general application of hydroxyapatites and HA-based composites (with addition of ZrO2 phase) for medicine (dentistry, maxillofacial surgery, orthopaedics or otolaryngology) to determine accurate percentage content of ZrO2 phase addition in the mixture that ensures maintaining of invariable or previously predicted dimensions of an implant or a coating after the process of sintering. The composites for the investigations were prepared by means of axial compaction of two ceramic powders (HA+ZrO2), which were then sintered at the temperature of 1300°C for two hours. The investigations aimed to obtain mathematical description that enables estimation of volume shrinkage in HAp + ZrO2 sinters after the process of sintering. In order to obtain a generalized dependence between contents of zirconium phase and shrinkage in the obtained sinters, regression and correlation concepts were employed. For the obtained experimental points several linear regression equations were matched using least squares method and correlation coefficient was calculated.

11

Modyfikacja warstwy wierzchniej biomateriałów na przykładzie tytanu metodą stopowania plazmowego

63%

Miklaszewski A. , Jurczyk M. , Jurczyk M.

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2011

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tom R. 83, nr 12

65-69

PL

W artykule przedstawiono wyniki modyfikacji warstwy wierzchniej tytanu metodą stopowania plazmowego powierzchni, a następnie jej trawienia elektrochemicznego. Zastosowanie prekursora nanokrystalicznego w istotny sposób wpływa na właściwości wyjściowe otrzymywanych warstw. Zastosowanie procesu mechanicznej syntezy prowadzi do zmniejszenia wielkości ziarna prekursora z jego częściową amorfizacją. Zmodyfikowaną przez proces stopowania plazmowego mikrostrukturę obserwowano przy użyciu mikroskopii optycznej. Dla zastosowanego nanoprekursora proszkowego otrzymano strukturę kompozytową warstwy składającą się z matrycy Ti (�alfa) oraz wydzieleń fazy TiB potwierdzoną badaniami strukturalnymi XRD. Uzyskano znaczący wzrost mikrotwardości otrzymanej warstwy 900 HV w porównaniu z podłożem 160 HV. Zaprezentowano wyniki badań biokompatybilności otrzymanej warstwy na hodowli komorkowej ludzkich osteoblastów w zestawieniu z mikrokrystalicznym tytanem. Wykonano testy odporności korozyjnej w roztworze Ringera w temperaturze 37°C, powierzchni po modyfikacji. Z analiz wynika, iż stopowanie plazmowe jest efektywną metodą wytwarzania warstw kompozytowych typu Ti+TiB.

EN

The paper presents the results of surface modification of pure titanium by boride microplasma alloying approach and following process of electrochemical treatment of obtained layer. Application of nanocrystaline precursor affects significant on properties of obtained layers. Applied mechanical alloying process of precursor powders leads to its partially amorphization and grain size decrease. Additionally, the modified microstructure was observed by optical microscopy. For used nano precursor, composite microstructure consisted from Ti (alfa) matrix and TiB precipitation confirmed by XRD analysis, were observed. The Vickers microhardness was significantly improve from 160 HV for original substrate to even 900 HV in obtained composite layer structure. In vitro biocompatibility test on human osteoblast cell culturefor obtained layer in comparison with pure microcrystalline titanium results were present. The surface corrosion resistance test in Ringer solution at 37°C, were performed on obtained layer. Results shows that boride microplasma alloying is an effective method of composite Ti+TiB layer structure formation.

12

Numerical and experimental analysis of spine’s transpedicular stabilizer

63%

Kiel M. , Marciniak J. , Basiaga M. , Szewczenko J. , Kus W. , Kokot G. , Wadek T.

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2010

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tom Vol. 41, nr 1-2

124-130

EN

Purpose: The aim of the work was a numerical and experimental analysis of spine’s transpedicular stabilizer on lumbar part of spine. The result of the analysis was determination of displacements of the stabilizers’ elements. Design/methodology/approach: To define numerical characteristic of the lumbar spine – transpedicular spine stabilizer system, the finite element method was applied. Geometrical models of lumbar part of spine and transpedicular stabilizer were discretized by SOLID95 element. The boundary conditions imitating phenomena in real system with appropriate accuracy were established. The experimental analysis was carried out for spine’s transpedicular stabilizers which were implanted on lumbar part of pig spine. The analysis was realized by means of testing machine MTS Insight with the use of videoextensometer. Numerical and experimental analysis were carried out for stabilizer made of stainless steel Cr-Ni-Mo. System was loaded by uniaxial compression with forces from 50 N to 1600 N. Findings: The result of analysis was calculation of relative displacements of the transpedicular stabilizer in a function of the applied loading; F = 700 - 1600 N for numerical model and F = 50 - 1600 N for experimental model. Research limitations/implications: The results of numerical analysis for transpedicular stabilizer obtained by finite element method were used to determine a construction features of the stabilizer, and to select mechanical properties of metallic biomaterial. The calculation of displacements for stabilizer show that the proposed type of stabilizer enables correct stabilization of spine. Practical implications: Both results of numerical and experimental analysis showed correct selection of mechanical properties of metallic biomaterial which were used to made the proposed type of transpedicular stabilizer. Originality/value: Advantageous results of analysis showed that the type of stabilizer may be used in clinical practice.

13

Physicochemical properties of Cr-Ni-Mo steel and Co-Cr-W-Ni alloy applied in urology

63%

Walke W. , Przondziono J.

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2010

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tom Vol. 39, nr 1

27-34

EN

Purpose: The main purpose of this study was to evaluate physical and chemical properties of Cr-Ni-Mo steel and Co-Cr-W-Ni alloy with modified surface, used for implants in human urinary system. Design/methodology/approach: Evaluation of physical and chemical properties of biomaterials was made on the ground of corrosion resistance tests and analysis of chemical composition of surface layer. Resistance to pitting corrosion was evaluated on the ground registered anodic polarisation curves by means of potentiodynamic method. Chemical composition investigations of the passive layer have been carried out with the use of X-ray Photoelectron Spectroscopy (XPS). Findings: Obtained test results show more favourable physical and chemical characteristics of Co-Cr-W-Ni alloy when compared to Cr-Ni-Mo steel. Suggested processes of surface treatment guarantee the improvement of corrosion resistance, and hence – biocompatibility of both metallic biomaterials in artificial urine. Research limitations/implications: Obtained test results indicate the necessity to select such physiological solution for corrosion tests, that would reflect specificity of the environment in which the implant will be functioning. Complementation of presented tests with measurements of stress and fatigue corrosion resistance will enable complex evaluation of behaviour of those biomaterials in urinary system environment. Practical implications: Analysis of test results shows favourable influence of suggested surface treatment of Co-Cr-W-Ni alloy. Samples with electrolytically polished and chemically passivated surface featured the best physical and chemical characteristics. Originality/value: After 30 days’ exposure in artificial urine solution passive layer created on the surface of Co-Cr-W-Ni alloy has better combination of physical and chemical properties than passive layer created on steel.

14

Ageing process influence on mechanical properties of polyamide - glass composites applied in dentistry

63%

Pusz A. , Szymiczek M. , Michalik K.

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2010

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tom Vol. 38, nr 1

49-55

EN

Purpose: The application of polymeric materials for medical purposes is growing very fast. Polymers have found applications in such diverse biomedical fields as tissue engineering, implantation of medical devices and artificial organs, prostheses, ophthalmology, dentistry, bone repair and many other medical fields. The requirements for materials used in the construction of removable dentures are becoming more and more demanding. The introduction of improved flexible materials has been a considerable advance. The aim of this work was to determine how the properties of thermoplastic materials change over time in terms of weight changes and artificial saliva sorption. Purpose of this paper was to evaluate the influence of the ageing process on mechanical properties of polyamide - glass composites applied in dentistry. Design/methodology/approach: Polyamide samples about the diversified content of the glass fibre were produced with method of the injection moulding. Denotation of the absorbency of artificial saliva was performed on standardized samples according to the norm. Samples were dried up to fixed mass, and then they were soaked in artificial saliva. Two temperatures of examination were applied 23°C and 30°C. Findings: An influence of the absorbability on mechanical properties of composites was determined. Examinations allowed to show that the absorbency of artificial saliva through composite is dependent on the temperature. Research limitations/implications: To fully evaluate the influence of the ageing process on mechanical properties of polyamide - glass composites applied in human body environment it is planned to continue described research. Simultaneous influence of the ageing process on mechanical properties of polyamide - glass composites shall be tested. Originality/value: Applying strengthened thermoplastics with glass fibre on dentures is a new look at materials applied in dentistry.

15

Wyznaczanie efektywnego współczynnika dyfuzji soli kadmu w biosorbencie alginianowym

63%

Kwiatkowska-Marks S. , Kopinski L. , Wójcik M.

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2011

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tom R. 19, nr 1

3-10

PL

Sorpcja na materiałach pochodzenia biologicznego jest uznawana za jedną z najbardziej obiecujących technik usuwania metali ciężkich ze ścieków. Bardzo efektywnymi biosorbentami jonów metali ciężkich są alginiany, (odnosi się to szczególnie do rozcieńczonych roztworów wodnych) , a ich dodatkową zaletą jest możliwość ponownego użycia po regeneracji. Przez odpowiednią obróbkę można otrzymać żele alginianów w postaci kulistych granulek. Szybkość sorpcji jonów metali ciężkich na granulkach alginianowych jest z reguły limitowana szybkością dyfuzji wewnętrznej, którą charakteryzuje efektywny współczynnik dyfuzji De. Istniejące metody wyznaczania De związane są ze stosowaniem pracochłonnych procedur analitycznych przy pomiarze stężenia jonów metali ciężkich. Opracowano nową metodę wyznaczania efektywnego współczynnika dyfuzji metali ciężkich w granulkach biosorbentu, która polega na zastosowaniu konduktometru do wyznaczania zmian stężenia danego metalu w roztworze i powiązaniu tych pomiarów z efektywnym współczynnikiem dyfuzji. Do badań używano alginianu sodu o niskiej lepkości, pochodzącego z firmy Sigma-Aldrich. Granulki alginianowe otrzymano przez wkraplanie roztworu biopolimeru do 0,05M chlorku wapnia, uzyskując granulki alginianu wapnia o zawartości alginianu: 1,5, 3,7 i 5,7% suchej masy. Otrzymane granulki zanurzano w O, IM roztworze siarczanu lub chlorku kadmu w celu zastąpienia jonów wapniowych kadmowymi. Badania prowadzono w układzie zamkniętym w stałej temperaturze 25°C. Sole kadmu znajdujące się w porach granulek alginianowych dyfundowały do wody destylowanej, a o szybkości procesu decydował efektywny współczynnik dyfuzji. Wzrost stężenia soli kadmu w roztworze prowadził do wzrostu przewodnictwa, które mierzono w odpowiednich odstępach czasu, używając konduktometru CPC-551 firmy Elmetron. Wyznaczony nową metodą efektywny współczynnik dyfuzji De soli kadmu w granulkach alginianowych wynosił od 0,37 do 0,73-10-9 [m2/s]. Wzrost zawartości alginianu w granulkach prowadził do zmniejszenia się wartości De i współczynnika spowolnienia, zgodnie z mechanizmem dyfuzji w porowatych nośnikach.

EN

Sorption by material of biological origin is recognized as an emerging technique for elimination of heavy metals from polluted streams. Very effective biosorbents of heavy metal ions are alginates, especially in the case of the diluted aqueous solutions. The alginate gels are obtained in the form of spherical beads by a suitable treatment. The rate of the heavy metal ions sorption by alginate beads is as a rule limited by the rate of internal diffusion characterized by the effective diffusivity De. Commonly used methods of De determination apply the labour-consuming procedures allowing to measure the heavy metal ions concejitration. In this work a method was developed which depends on using a con-ductometer to determine the changes of cadmium salts concentrations in solution and connection of these determinations with effective diffusivity. Sodium alginate purchased from Sigma-Aldrich was used in preparation of alginate biosorbent. In the first step the calcium alginate beads were obtained by dripping the sodium alginate solution into 0.05M CaCl2. By this procedure biosorbent beads of three different concentrations (1.5, 3.7 and 5.7% w/w) were prepared. In the next step the beads were soaked in 0.1 M CdSO4or CdCl2 solutions to replace calcium with cadmium ions. The determination of effective diffusity was carried out in a closed system, at a constant temperature 25°C. Cadmium salts diffused from the pores of beads to distilled water and the process was limited by diffusion. The increase of CdSO4 or CdCl2 concentration in solution causes the increase of conductivity. At selected time intervals conductMry of sołution was measured by microcomputer conductometer CPC-551 from Elmetron. These data were used for calculation of effective diffusivity De which ranged from 0,37-10 9 to 0,73-10 9 [m2/s]. The effective diffusivity decrease with the increase of alginate concentration. It is in accordance with a mechanism of diffusion in porous carriers.

16

Wpływ obróbki cieplnej hydroksyapatytu dotowanego tytanem (TiHA) na właściwości i zachowanie w warunkach in vitro kompozytów na bazie siarczanu(VI) wapnia i TiHA

63%

Czechowska J. , Paszkiewicz Z. , Zima A. , Pijocha D. , Ślósarczyk A.

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2011

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tom T. 63, nr 4

758-764

PL

W ostatnich latach coraz większe zainteresowane budzą biomateriały do wypełniania ubytków kostnych wykazujące właściwości wiążące in situ. Obecnie na rynku dostępnych jest wiele komercyjnych produktów, jednak wciąż nie ustają próby zmierzające do wytworzenia nowego substytutu kostnego, o ulepszonych właściwościach mechanicznych i biologicznych. Materiały oparte na fosforanach(V) wapnia (włącznie z hydroksyapatytem, HA) cieszą się szczególnym zainteresowaniem ze względu na ich doskonalą biozgodność oraz bioaktywność. Siarczan(VI) wapnia od szeregu lat używany jest do celów klinicznych, a jako wypełniacz kostny jest dobrze tolerowalny przez organizm. W obecnych badaniach opracowano dwufazowy, wiążący substytut kostny na bazie siarczanu(VI) wapnia oraz dotowanego tytanem hydroksyapatytu. Do wytworzenia tego biomateriału użyto półwodnego siarczanu(VI) wapnia (CSH) oraz trzech proszków hydroksyapatytowych dotowanych tytanem (TiHA): surowego oraz kalcynowanych w 800 i 1250°C. Celem badań było określenie wpływu obróbki cieplnej hydroksyapatytu dotowanego tytanem na czas wiązania, właściwości mechaniczne oraz zachowanie w warunkach in vitro w sztucznym osoczu krwi (SBF) kompozytu opartego na siarczanie(VI) wapnia i TiHA. Rezultaty badań wskazują, że materiały wiążące TiHA-CS są biokompatybilne, łatwo kształtowalne oraz posiadają potencjalne zastosowanie do uzupełniania ubytków kostnych.

EN

Biomaterials with the self-setting in situ properties for the use in human bone tissue augmentation have attracted increasing attention in recent years. Currently many commercial products exist on the market, however the efforts still proceed to achieve a novel bone substitute with improved mechanical and biological properties. Calcium phosphate based materials, including hydroxyapatite (HA), have been of special interest due to their excellent biocompatibility and bioactivity. Calcium sulfate has also a long history of clinical use and it is known to be well-tolerated by organism when used as a bone filler. In this study, a biphasic, self-setting bone substitute was developed, basing on calcium sulfate and titanium doped hydroxyapatite. Calcium sulfate hemihydrate (CSH) and three different Ti doped hydroxyapatite powders (TiHA): raw and calcined at 800°C and 1250°C were used to form the new biomaterial. The aim of this study was to investigate how heat treatment of titanium doped hydroxyapatite influenced the setting time, mechanical properties and in vitro behaviour in simulated body fluid (SBF) of the calcium sulfate - TiHA composites. The results of our studies suggest that TiHA-CS self-setting materials are biocompatible, easily shapeable and have a potential to be applied for bone substitution.

17

Nowe rozwiązania w zakresie biotribologii i biomateriałów. Cz. 2 Stanowisko do badań zużyciowych elementów endoprotez stawu biodrowego

63%

Ozwoniarek J. , Wiśniewska-Weinert H. , Lisowski J. , Kędzia Ł.

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2007

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tom T. 18, nr 1

35-40

PL

W artykule przedstawiono budowę stawu biodrowego człowieka zwracając uwagę na jego podobieństwo do łożyska kulisto-panewkowego. Zaprezentowano zbudowane w Instytucie Obróbki Plastycznej w Poznaniu stanowisko do badania elementów stawu biodrowego człowieka, ktorego idea budowy powstała na podstawie reakcji podłoża podczas chodu człowieka. Przedstawiono również zaplanowane do realizacji na ww. stanowisku badania.

EN

In the article the structure of human hip joint is presented, emphasizing its similarity with ball-acetabulum bearing. The stand built in Metal Forming Institute in Poznań for tests of human hip joint’s components, which concept derived from substrate reaction during human walk, is introduced. Planned tasks to be performed on the above mentioned test stand are also shown.

18

The elimination of micropores and surface defects in aramid-silicon laminated materials with special properties

63%

Dobrzański L. A. , Pusz A. , Nowak A. J.

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2009

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tom Vol. 35, nr 2

121-128

EN

Purpose: Development of the manufacturing technology of aramid-silicon laminated material and define of the micro-cavities amount during production of the laminates and identification of their influence on product properties with assumed medical implantation. Design/methodology/approach: Aramid-silicon laminated material was made by method of manual formation of laminates, that is impregnation of reinforcement with matrix, to hardening silicone process using hardening methods connected with hot. Created material was observed on Olimpus HIGLIGHT 2000 optical microscope with magnification 40x. Findings: The results show that the preliminary manufacturing technology of aramid-silicon laminated materials allows to create a material with specific and special properties. Aramid-silicone laminate could be used in medicine for example as gullet prosthesis. Research limitations/implications: Carried out investigations show the problem with cautioning and ageing which are very important in having proper percentage of intensifier in developed material. Originality/value: Taking into account the material specific properties one can suppose that the aramid-silicon laminated material would be useful in medicine. Aramid silicone laminate could be attractive alternative for composite material used in medical and others purposes.

19

Nowe rozwiązania w zakresie biotribologii i biomateriałów. Część 1 Wymagania stawiane biomateriałom stosowanym na endoprotezy stawów

63%

Ozwoniarek J. , Wiśniewska-Weinert H. , Leshchynsky V. , Kędzia Ł. , Gierzyńska-Dolna M.

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2006

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tom T. 17, nr 3

29-36

PL

Wzrost zapotrzebowania na różnego rodzaju implanty wynikający z wydłużającego się czasu życia człowieka, skażenia środowiska, rosnącej ilości kolizji samochodowych i związanej z tym dużej ilości urazów układu kostno-stawowego uzasadnia potrzebę i celowość intensyfikacji prac w dziedzinie biomateriałów i biotribologii. W artykule przedstawiono wymagania stawiane materiałom stosowanym na endoprotezy stawów człowieka oraz sposoby ich weryfikacji. Omówiono rodzaje tarcia występujące w stawach. Autorzy omówili zamierzenia oraz kierunki wstępnych prac badawczo-rozwojowych prowadzonych przez Instytut Obróbki Plastycznej w Poznaniu w zakresie biotribologii i biomateriałów, zastosowania nanotechnologii i proszków spiekanych na elementy endoprotez a także badań tarciowo-zużyciowych prowadzonych na symulatorach. Badania te wpisują się w priorytetowy kierunek badań Krajowego Programu Ramowego (KPR) - 6.1. Nanomateriały i nanoukłady wielofunkcyjne.

EN

The growing length of human life, environment pollution, increasing number of car accidents and the resulting injuries of the osseous system cause growing demand for various kinds of implants and, consequently, necessitate intensive works on biomaterials and biotribology. The paper presents the requirements to be met by the materials used for human articulation endoprostheses and the methods of their verification. The kinds of friction present in the articulations are discussed. The authors have shown the intentions and directions of the initial research and development works conducted by the Metal Forming Institute in Poznań in the field of biotribology and biomaterials, application of nanotechnology and sintered powders as materials for the elements of endoprostheses, as well as friction and wear investigations performed on simulators. Those investigations can be included in the priority direction of the investigation of the National Framework Program (KPR) - 6.1. Multifunctional nanomaterials and nanosystems.

20

Odporność korozyjna kompozytów 316L+HAp

63%

Dudek A. , Włodarczyk R.

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2010

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tom R. 10, nr 4

312-316

PL

Zapotrzebowanie na nowe materiały w dziedzinie medycyny ciągle wzrasta. Wielu pacjentów po zaimplantowaniu posiada bowiem skłonność do alergii na zastosowane biomateriały lub na niektóre ich składniki. Jednym z głównych powodów występowania zjawisk patologicznych są metale i stopy wykorzystywane w implantologii. W związku z powyższym naukowcy, lekarze oraz technicy podejmują próby stworzenia nowoczesnych materiałów, które uwzględniałyby wszelkie aspekty biologiczne. Kolejnym celem stawianym nowoczesnej technice jest indywidualne dopasowanie materiałów implantacyjnych do konkretnego zastosowania, w jednym przypadku niezbędne są bowiem wysokie własności mechaniczne, w innych zaś struktura czy skład fazowy. W ramach badań metodą metalurgii proszków oraz metodą HP-HT (High Pressure - High Temperature) wykonano kompozyty metaliczno-ceramiczne 316L+HAp z różnym dodatkiem fazy ceramicznej. Celem pracy było wykonanie badań odporności korozyjnej, mikrostrukturalnych oraz własności wytrzymałościowych otrzymanych kompozytów w roztworze Ringera.

EN

Demand for new materials used in medicine is constantly on the increase. An essential task of material engineering is to satisfy material needs in medicine applications. A number of patients are susceptible to allergies to the used biomaterials or some of their components. Main cause of appearance of these pathologic phenomena is metals and the alloys used in prosthesis. Due to this fact, scientists, doctors and technicians have made a variety of attempts to develop modern materials which would include all biological aspects. Another goal imposed on modern technologies is to provide individual matching of implantation materials with particular applications, as some cases require enhanced mechanical properties while the others call for structure or phase composition. Long-lasting implants (joint prostheses, dental implants), typically made of metals and their alloys, are characterized by improved mechanical properties but low corrosion resistance and biocompatibility. Thus, the attempts should be made to develop materials with enhanced functional properties for application in medicine. One of the methods to obtain these materials is to develop composite-based implants that combine good mechanical properties of metallic material with biotolerance of ceramic materials. During the investigations, combined metallic and ceramic composites 316L+HAp were prepared using powder metallurgy and HP-HT method (High Pressure - High Temperature), with different percentage of addition of ceramic phase. The investigations were focused on testing of microstructure, mechanical properties and corro-sion resistance of the obtained composites in Ringer's solution.