Wyniki wyszukiwania - Biblioteka Nauki

1

Hyperthermia can differentially modulate the repair of doxorubicin-damaged DNA in normal and cancer cells*.

100%

Blasiak J. , Widera K. , Pertyński T.

Acta Biochimica Polonica

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2003

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tom 50

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nr 1

191-195

EN

Hyperthermia can modulate the action of many anticancer drugs, and DNA repair processes are temperature-dependent, but the character of this dependence in cancer and normal cells is largely unknown. This subject seems to be worth studying, because hyperthermia can assist cancer therapy. A 1-h incubation at 37°C of normal human peripheral blood lymphocytes and human myelogenous leukemia cell line K562 with 0.5 μM doxorubicin gave significant level of DNA damage as assessed by the alkaline comet assay. The cells were then incubated in doxorubicin-free repair medium at 37°C or 41°C. The lymphocytes incubated at 37°C needed about 60 min to remove completely the damage to their DNA, whereas at 41°C the time required for complete repair was shortened to 30 min. There was also a difference between the repair kinetics at 37°C and 41°C in cancer cells. Moreover, the kinetics were different in doxorubicin-sensitive and resistant cells. Therefore, hyperthermia may significantly affect the kinetics of DNA repair in drug-treated cells, but the magnitude of the effect may be different in normal and cancer cells. These features may be exploited in cancer chemotherapy to increase the effectiveness of the treatment and reduce unwanted effects of anticancer drugs in normal cells and fight DNA repair-based drug resistance of cancer cells.

2

Evaluation of the performance of designed coaxial antennas for hyperthermia using simulation and experimental methods

100%

Ibitoye A. Z. , Ogese O. C. , Adedokun M. B. , Habeebu M. Y. , Nwoye E. O. , Aweda A. M.

Polish Journal of Medical Physics and Engineering

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2021

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tom Vol. 27, Iss. 1

109--117

EN

Introduction: Antenna geometries and tissue properties affect microwave energy distributions during microwave ablation procedures. There is paucity information on the potential of antenna fabricated from a thick semi-rigid coaxial cable in the field of microwave thermal therapy. This study aimed at comparing the performance of two dual-slot antennas designed from different semi-rigid coaxial cables for the ablation of a liver tumour using numerical simulation and experimental validation methods. Materials and Methods: COMSOL Multiphysics software was used for designing dual-slot antennas and as well as to evaluate microwave energy deposition and heat distribution in the liver tissue. Experimental validations were conducted on the ex-vivo bovine livers to validate the simulation results. Results: Thick antenna developed in this study produced a higher sphericity index, larger ablation diameter and reduced backward heating along the antenna shaft than the existing one. The experimental validation results also indicate significant differences between the two antennas in terms of ablation diameters (p = 0.04), ablation lengths (p = 0.02) and aspect ratios (p = 0.02). Conclusion: Based on the findings in this study, antenna fabricated from a thick coaxial cable has a higher potential of localizing microwave energy in the liver than conventional antennas.

3

Distribution of the Temperature in Human Body in RF Hyperthermia

100%

Kurgan E. , Gas P.

Przegląd Elektrotechniczny

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2009

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tom R. 85, nr 12

96-99

EN

Knowledge of the temperature distribution in human body is of great importance in hyperthermial treatment of tumors. In this article first distribution of induced current density in tissues is calculated and next bioheat equation is solved. Dependence of sensitivity of the maximum temperature distribution in the body from different model parameters are calculated.

PL

Wiedza o rozkładzie temperatury w ciele człowieka ma wielkie znaczenie w leczeniu guzów nowotworowych. W niniejszym artykule na początku wyznaczono gęstość indukowanego prądu w tkankach biologicznych, a następnie rozwiązano biologiczne równanie ciepła. Ponadto zbadano zależność wrażliwości rozkładu maksymalnej temperatury w ciele człowieka od wybranych parametrów modelu.

4

Investigation of magnetite Fe3O4 nanoparticles for magnetic hyperthermia

100%

Surowiec Z. , Miaskowski A. , Budzyński M.

Nukleonika

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2017

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tom Vol. 62, No. 2

183--186

EN

The paper presents the investigation of magnetic nanoparticles (MNPs) dedicated to hyperthermia application. The crystal structure and size distributions have been determined by means of transmission electron microscope (TEM) and X-ray diffraction (XRD). Magnetic properties of the nanoparticles were tested by Mössbauer spectroscopy together with calorimetric experiments. The Mössbauer spectroscopic study of MNPs revealed the existence of a superparamagnetic phase. The relative contribution of the relaxing component to the total spectrum at room temperature was about 10%. The heating effect of these MNPs under alternating magnetic field was examined. The temperature increase has reached 5°C in 10 min. The preliminary temperature rise suggests that the investigated materials are applicable for hyperthermia.

5

Effects of Ambient Temperature on Physiological Responses to Incremental Exercise Test

88%

Aleksander T. , Szczepan W. , Tomasz P. , Zbigniew S. , Anna T. , Tomasz C.

Journal of Human Kinetics

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2010

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tom 26

57-64

EN

Physiological variables are regularly analyzed by coaches and sport scientists during an incremental exercise test (IET) until exhaustion. Physiological and biochemical responses of the body are modified upon exercising in the heat as well as results obtained in the IET. Heat changes the validity of these results to be used when prescribing or monitoring training processes and predicting performance in athletesTo determine the effect of ambient temperature on physiological responses, twelve physically active men completed IET on the cycle ergometer in three ambient temperatures: 23°C (T23), 31°C (T31) and 37°C (T37).We measured continuously: rectal temperature (Tre) and aural canal temperature (Tac), heart rate (HR), O2 CO2 respiratory rate (RR), tidal volume (TV), and minute ventilation (VE). Blood samples for pl LA-pf were taken before, at the end of each exercise step and 3 minutes after the test ended.The exercise duration (DE) and energy expenditure (EE) to reach the threshold of decompensated metabolic acidosis (TDMA) decreased (p<0.05) in T31 (11.27 ± 3.03 minutes; 86.2 ± 24.2 kJ) and T37 (10.72 ± 2.76 minutes; 79.5 ± 21.3 kJ) in comparison to T23 (13.10 ± 2.30 minutes; 108.8 ± 23.9 kJ), with no differences observed in pl LA-pf, VE, O2 or Tre. We observed an increase (p<0.05) in pl LA-pf after tests in T31 (11.08 ± 1.89 mmol/L) and T37 (11.94 ± 2.25 mmol/L) in comparison to T23 (10.26 ± 2.30 mmol/L), with no differences observed in O2 max, end Tre, EE and DE to exhaustion.The TDMA occurs faster and at a lower WL, while performing IET in 31°C and 37°C. Coaches sport scientists should consider these factors when conducting IET to assess the threshold level and performance of athletes.

6

The Effect of a Simulated Basketball Game on Players’ Sprint and Jump Performance, Temperature and Muscle Damage

88%

Pliauga V. , Kamandulis S. , Dargevičiūtė G. , Jaszczanin J. , Klizienė I. , Stanislovaitienė J. , Stanislovaitis A.

Journal of Human Kinetics

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2015

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tom 46

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nr 1

167-175

EN

Despite extensive data regarding the demands of playing basketball, the relative importance of factors that cause fatigue and muscle potentiation has been explored only tentatively and remains unclear. The aim of this experimental field study was to assess changes in leg muscle power and relate these changes to body temperature modifications and indices of exercise-induced muscle damage in response to a simulated basketball game. College-level male basketball players (n=10) were divided into two teams to play a simulated basketball game. Ten-meter sprint and vertical counter-movement jump tests, core body temperature and creatine-kinase activity were measured within 48 h after the game. The participants’ body temperatures increased after a warm-up (1.9%, p<0.05), continued to increase throughout the game, and reached 39.4 ± 0.4°C after the fourth quarter (p<0.05). The increase in temperature during the warm-up was accompanied by an improvement in the 10-meter sprint time (5.5%, p<0.05) and jump height (3.8%, p<0.05). The players were able to maintain leg power up to the fourth quarter, i.e., during the major part of the basketball game. There was a significant increase in creatine-kinase at 24 h (>200%, p<0.05) and 48 h (>30%, p<0.05) after the game, indicating damage to the players’ muscles. The basketball players’ sprint and jump performance appear to be at least in part associated with body temperature changes, which might contribute to counteract fatigue during the larger part of a basketball game.

7

Thermo-magnetic stability of magnetic Fe3O4 nanoparticles for hyperthermia

88%

Pan Y. M. , Zhang W. , Hu Z. F. , Feng Z. Y. , Zhang X. P.

Materials Science Poland

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2020

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tom Vol. 38, No. 4

637--643

EN

Monodispersed Fe3O4 magnetic particles adsorbed by amylase (such as citric acid (CA), carboxymethyl chitosan (CMCH) and β-cyclodextrin (CD)) were prepared by means of co-precipitation method. The absorption character of the samples was investigated by FT-IR, TG and VSM. It was found that the carboxyl (COOH groups) of amylase reacted with the hydroxyl (OH groups) on the surface of Fe3O4 particles, resulting in the formation of iron carboxylate that was adsorbed onto Fe3O4. The induction heating properties of the magnetic Fe3O4 nanoparticles in an alternating current magnetic field were also investigated and the thermo-magnetic stability in induction heating was discussed.

8

Influence of wire geometry on temperature distribution in human body during rf hyperthermia

75%

Gas P.

Prace Instytutu Elektrotechniki

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2011

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tom Z. 252

133-143

EN

A numerical model which is an example of local-regional RF hyperthermia is presented. Human body is surrounded by an elliptical wire with exciting current and the electromagnetic energy is concentrated within the tumor. The presented issue is therefore a coupling of the electromagnetic field and the temperature field. For simplification a two-dimensional model which is a cross section through the human body is adopted. Using the finite element method exciting current density in human body has been calculated, and then bioheat equation under transient-time condition has been resolved. Finally, the obtained simulation results for several wire configurations are presented.

PL

W niniejszej pracy przedstawiono model numeryczny stanowiący przykład zastosowania lokalno-regionalnej hipertermii o częstotliwości radiowej. Ciało człowieka otoczone jest eliptycznym przewodem z wymuszającym prądem, a energia elektromagnetyczna koncentrowana jest wewnątrz guza. Dla uproszczenia przyjęto model dwuwymiarowy stanowiący przekrój poprzeczny przez ciało człowieka. Wykorzystując metodę elementów skończonych obliczono gęstość prądu indukowanego w ciele człowieka, a następnie rozwiązano biologiczne równanie ciepła dla przypadku zmiennego w czasie. Na końcu zestawiono uzyskane wyniki symulacji dla kilku konfiguracji przewodu.

9

Synthesis and magnetic properties of Fe2O3 nanoparticles for hyperthermia application

75%

Szmajnta K. , Szindler M. M. , Szindler M.

Archives of Materials Science and Engineering

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2021

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tom Vol. 109, nr 2

80--85

EN

Purpose: The main purpose of this publication is to bring closer co-precipitation method of magnetic particles synthesis. Procedure of examining and characterisation of those materials was also shown. Design/methodology/approach: During the work, the properties and possible biomedical application of the material produced were also examined. Surface morphology studies of the obtained particles were made using Zeiss's Supra 35 scanning electron microscope and S/TEM TITAN 80-300 transmission electron microscope. In order to confirm the chemical composition of observed layers, qualitative tests were performed by means of spectroscopy of scattered X-ray energy using the Energy Dispersive Spectrometer (EDS). The Raman spectra of the samples were measured with a InVia Raman microscope by Renishaw. Magnetic properties of hematite nanoparticles were made using VSM magnetometer. Findings: Using VSM magnetometer proved that obtained material is mixture of ferromagnetic and superparamagnetic domain. Practical implications: Magnetic Nanoparticles (MNPs) has been gaining an incrementally increasing interest of scientists in the biomedical areas. Presented materials can be used in the hyperthermia phenomena which can be used in precise cancer treatment. Originality/value: Specific magnetic properties which determinate obtained material to be well for hyperthermia phenomena.

10

Life-threatening conditions in psychiatry - neuroleptic malignant syndrome (NMS)

75%

Kucmin T. , Kucmin A. , Plowas-Goral M. , Jojczuk M.

Journal of Pre-Clinical and Clinical Research

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2015

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tom 09

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nr 1

EN

The introduction of neuroleptics in the 1950’s was a turning point in psychiatric treatment. The new drugs brought hope to millions of patients and their doctors. However, there were also some side-effects, one of which is Neuroleptic malignant syndrome (NMS), a rare complication of antipsychotic treatment and untreated it may lead to mortality as high as 20%. The incidence of NMS, estimated to be 0.01–0.02%, has decreased significantly probably due to higher awareness of the diseases and shift to atypical antipsychotics. The aim of this study was to present the signs and symptoms of this rare condition and describe management possibilities since this condition is observed not only in psychiatric departments but also in emergency rooms. NMS is thought to be related to change caused by neuroleptics within the central nervous system due to dopamine D2 receptor antagonism, especially nigrostriatal pathways and the hypothalamus. There are three symptoms which are considered as major and indicate a high probability of NMS: muscle rigidity, hyperthermia (core body temperature above 38.5 °C), and elevated creatine phosphokinase concentration (above 1000 U/l). NMS is a diagnosis of exclusion and clinicians must be vigilant in detecting early signs of NMS. The basic management in NMS is antipsychotic discontinuation and proper supportive care of the patient (vital signs monitoring, hydration, correction of electrolyte and acid-base disturbances). In more severe cases, the introduction of bromocriptine or dantrolene, as well as benzodiazepines, may indicated. Further usage of neuroleptic in patients with a history of NMS should be with care, and low doses of low-potency neuroleptics or atypical neuroleptics seem to be the best treatment choice.

11

Treatment of Tumors Located in the Human Thigh using RF Hyperthermia

75%

Kurgan E. , Gas P.

Przegląd Elektrotechniczny

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2011

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tom R. 87, nr 12b

103--106

EN

In this publication a numerical model and simulation results of electric field, induced current denslty and temperature distributions inside human thigh heated by external RF hyperthermia are presented. For simplicity, the heat transfer problem is treated in two-dimensions with semi infinite tissue model. The bioheat equation under a transient-time condition is solved to determine the temperature distributions inside the tumor and theat removal due to the blood circulation is also taken into account in the presented model.

PL

W artykule przedstawiono model numeryczny i wyniki symulacji pola elektrycznego, gęstości prądu indukowanego wewnątrz ludzkiego uda grzanego przy użyciu zewnętrznej RF hipertermii. Dla uproszczenia problem wymiany ciepła jest rozpatrywany w dwóch wymiarach dla pół-nieskończonego modelu tkanek. W celu określenia rozkładu temperatury wewnątrz guza i w otaczających go tkankach rozwiązano biologiczne równanie ciepła w przypadku zmiennym w czasie. W rozważanym modelu uwzględniono również odprowadzanie ciepła wynikające z krążenia krwi.

12

Changes in the ultrastructure and functions of immunocompetent cells under the influence of external heating, interleukin 1beta and leukocytic pyrogen

75%

Murzenok P. P. , Netukova N. I.

Archivum Immunologiae et Therapiae Experimentalis

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1994

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tom 42

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nr 4

13

Insecticides and thermoregulation in insects

75%

Tegowska E.

Pestycydy

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2003

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nr 1-4

14

Hyperthermia induced modification of erythrocyte membrane susceptibility to interaction with unsaturated fatty acids

75%

Rybczynska M.

Applied Biology Communications. Lublin Scientific Center

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1993

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tom 03

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nr 3-4

15

Temperature inside tumor as time function in RF hyperthermia

63%

Gas P.

Przegląd Elektrotechniczny

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2010

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tom R. 86, nr 12

42-45

EN

A simplified 2-D model which is an example of regional RF hyperthermia is presented. Human body is inside the wire with exciting current and the electromagnetic energy is concentrated within the tumor. The analyzed model is therefore a coupling of the electromagnetic field and the temperature field. Exciting current density in human body has been calculated using the finite element method, and then bioheat equation in timedepended nonstationary case has been resolved. At the and obtained results are presented.

PL

W niniejszej pracy przedstawiono uproszczony model dwuwymiarowy stanowiący prosty przykład zastosowania regionalnej hipertermii o częstotliwości radiowej, w której ciało człowieka znajduje się wewnątrz przewód z wymuszającym prądem, a energia elektromagnetyczna zostaje skupiona w środku guza. Analizowany model stanowi zatem sprzężenie pola elektromagnetycznego i pola temperatury. Posługując się metodą elementów skończonych na wstępie wyznaczono gęstość prądu indukowanego w ciele człowieka, a następnie rozwiązano biologiczne równanie ciepła w przypadku niestacjonarnym zależnym od czasu. Na końcu zestawiono uzyskane wyniki.

16

Termoterapia z użyciem magnetycznych nanocząstek

63%

Jurczyk M.

Current Gynecologic Oncology

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2010

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tom 8

|

nr 2

82-89

EN

Nanoscale magnetic materials may have several potential applications in the biomedical area. An example thereof are superparamagnetic iron oxide nanoparticles, which, due to large own surface and ability to interact with various tissues, are used to detect and analyze biological molecules, in targeted drug delivery, for contrast enhancement in magnetic resonance imaging studies and, last but not least, in therapeutic hyperthermia. When used for medical purposes, magnetic nanoparticles often require coating with a biocompatible polymer, preventing its detection by the immune system, encapsulation by plasma proteins and excretion, while at the same time facilitating binding with organic complexes, which subsequently may accumulate in definite pathological foci. Widespread use of magnetic nanoparticles is associated with heat generation. When placed within neoplastic tissue and exposed to alternating external magnetic field, magnetic nanoparticles generate a local heating effect. Local elevation of tissue temperature has a potent cytostatic effect mediated by denaturation of proteins and destruction of intracellular structures, leading to reduction of tumor mass. Temperature obtained within the tumor depends on properties of magnetic nanoparticles used and parameters of external magnetic field applied, i.e. amplitude and frequency of field oscillations. This physical phenomenon results in direct destruction of tumor cells. Furthermore, local elevation of body temperature contributes to enhanced effectiveness of chemo- and radiotherapy. The paper is a review of current applications of superparamagnetic metal nanoparticles in oncology.

PL

Nanomateriały magnetyczne mogą znaleźć szerokie zastosowanie zarówno w naukach biologicznych, jak i medycznych. Przykładem takich materiałów są superparamagnetyczne nanocząstki żelaza, które z uwagi na dużą powierzchnię właściwą i możliwość oddziaływania z różnymi tkankami są stosowane między innymi w detekcji i analizie biocząsteczek, docelowym transporcie leków, poprawie kontrastu przy badaniach metodą rezonansu magnetycznego i hipertermii. Do zastosowań medycznych nanocząstki magnetyczne wymagają często pokrycia biokompatybilnym polimerem, który z jednej strony ekranuje cząstkę przed układem immunologicznym, uniemożliwiając otoczenie jej białkami plazmy i usunięcie z organizmu, z drugiej zaś ułatwia wiązanie innych kompleksów organicznych, które mogą być transportowane do określonych obszarów patologicznych. Szerokie zastosowanie medyczne magnetycznych nanocząstek jest związane z efektem generowania ciepła. Jeżeli nanocząstki magnetyczne zostaną umiejscowione w zmienionym nowotworowo obszarze ciała, to w obecności zmiennego zewnętrznego pola magnetycznego można uzyskać efekt cieplny. Uśmiercając komórki nowotworowe i niszcząc białka oraz struktury wewnątrzkomórkowe wygenerowaną w tych miejscach wysoką temperaturą, możemy powodować zmniejszenie się guza. Wysokość uzyskanego przez nas poziomu temperatury w guzie nowotworowym zależy od właściwości użytych magnetycznych nanocząstek oraz od parametrów przyłożonego zmiennego pola magnetycznego (amplituda, częstotliwość). To zjawisko fizyczne wykorzystuje się do bezpośredniego niszczenia komórek nowotworowych. Dodatkowo wzrost temperatury obszaru ciała chorego zwiększa efektywność zastosowanej chemio- lub radioterapii. W pracy zaprezentowano przegląd zastosowania superparamagnetycznych cząsteczek metali w terapii nowotworowej.

17

Influence of tissue parameters on deep body RF hyperthermia

63%

Kurgan E. , Gas P.

Poznan University of Technology Academic Journals. Electrical Engineering

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2010

|

tom No. 63

63-68

EN

Hyperthermia has become a useful form of cancer therapy. In this paper some numerical results based on a two-dimensional homogeneous model of human body are presented. First distribution of the electromagnetic field components are calculated and next bioheat equation is solved. At the end temperature distribution in the body from different model parameters are calculated.

18

Nanotermia oraz przykłady zastosowania pól elektromagnetycznych w medycynie

63%

Barglik J. , Dołęga D.

Przegląd Elektrotechniczny

|

2010

|

tom R. 86, nr 7

15-19

PL

Artykuł dotyczy problematyki związanej z nanotermią oraz wybranymi zastosowaniami pól elektromagnetycznych w medycynie. Od wielu lat w naukach medycznych stosowane są metody magnetoterapii oraz magnetostymulacji. W ciągu ostatnich kilkunastu lat nastąpił znaczny rozwój nanotechnologii. Połączenie medycyny, nanotechnologii oraz elektrotermii widoczne jest szczególnie w procesie hipertermii z użyciem magnetycznych nanocząstek. Nowa dziedzina jaką jest nanotermia wiąże się z zastosowaniem nanocząstek w celu nagrzewania bądź przegrzewania, jak ma to miejsce w hipertermii, ściśle określonych i ograniczonych objętości (np.: tkanek nowotworowych).

EN

This article relates to nanothermy problems and selected applications of electromagnetic field in medicine. Magnetoteraphy and magnetostimulation methods are used in medical science from many years. Nanotechnology has evolved much in recent years. The hyperthermia with using of magnetic nanoparticles arised due to connection of medicine, nanotechnology and electrical heating engineering. Nanothermy, the new branch of knowledge, is connected with application of nanoparticles to heating or overheating, like in the hyperthermia, tightly limited and specified volumes (like tumors).

19

The system for complex magnetic susceptibility measurement of nanoparticles with 3D printed carcass for integrated receive coils

63%

Midura M. , Wróblewski P. , Wanta D. , Domański G. , Stosio M. , Kryszyn J. , Smolik W. T.

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

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2021

|

tom T. 11, nr 1

4--9

EN

The article concerns the research on the properties of core-shell superparamagnetic nanoparticles in the context of their use in medicine for diagnostics and therapy. The article presents a system for impedance (AC) spectroscopy of nanoparticles with a new arrangement of receive coils. A significant modification was the position of the reference coil in relation to the receive coils as well as the method of winding and routing the wires on the carcass. The 3D printing technique was used in the production of the measuring coil system. The aim of the work was to experimentally verify the developed measurement system and analyze its properties. The system tests were carried out at low frequencies ranging from 2 to 50 kHz. Complex magnetic susceptibility was measured for superparamagnetic iron oxide nanoparticles in polymer shells in a physiological saline solution. The obtained results confirmed the relevance of the concept of the measurements. In summary, the observed properties of the realized system are discussed and further directions of its development are proposed.

PL

Artykuł dotyczy badań właściwości nanocząstek superparamagnetycznych typu rdzeń-powłoka w kontekście wykorzystania ich w medycynie do diagnostyki jak i terapii. W artykule przedstawiono układ do spektroskopii impedancyjnej (AC) nanocząstek z nowym układem cewek odbiorczych. Istotną modyfikacją była pozycja cewki referencyjnej względem cewek odbiorczych jak również sposób nawijania i prowadzenia przewodów na karkasie. W realizacji układu cewek pomiarowych wykorzystana została technika druku 3D. Celem pracy była eksperymentalna weryfikacja opracowanego układu pomiarowego i analiza jego własności. Testy układu zostały przeprowadzone dla niskich częstotliwości w zakresie od 2 do 50 kHz. Pomiary zespolonej podatności magnetycznej dokonano dla nanocząstek superparamagnetycznych tlenku żelaza w otoczkach polimerowych w roztworze soli fizjologicznej. Uzyskane wyniki potwierdziły poprawność koncepcji realizacji pomiarów. W podsumowaniu omówiono zaobserwowane własności zrealizowanego układu i zaproponowano dalsze kierunki jego rozwoju.

20

Activity of oxidative enzymes in neurolgia in vitro after hyperthermia

63%

Renkawek K. , Majkowska J.

Folia Histochemica et Cytobiologica

|

1984

|

tom 22

|

nr 3-4