Wyniki wyszukiwania - Biblioteka Nauki

1

New trends in theranostics

100%

Moskal P. , Stępień E. Ł.

Bio-Algorithms and Med-Systems

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2021

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tom Vol. 17, no. 4

199--202

2

Microprocessor-based air plethysmograph for the examination of compressed tissue of limbs

100%

Fąs T. , Kaczmarek M.

Acta of Bioengineering and Biomechanics

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2022

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tom Vol. 24, no. 3

41--48

EN

The aim of the article is to propose a simple microprocessor-based air plethysmograph that uses a measurement of changes in air pressure in a closed cuff to determine the changes in the volume of the compressed limb. Methods: The microprocessor-controlled measurement system applied pressure to the object (ultimately the limb) by pumping air into the cuff surrounding the object. Changes in pressure and air temperature in the cuff over time were recorded. The results supplemented with the calibration procedure made it possible to determine the changes in the volume of the object. Results: Measurement-independent calibration and temperature correction of pressure changes in the system proved to be necessary components of the measurement procedure for volume changes. When comparing the device test results with the actual changes observed with the limb model, there was a discrepancy between 0.2 and 0.7 percent of the total volume under the cuff. Conclusions: Studies have shown that the proposed air plethysmograph is useful for assessing the changes in the volume of the limb model within the range that are expected in the diagnosis of lymphedema. The solution is a cheaper and less complicated alternative than most of the available methods of measuring changes in the volume of edema tissue under controlled pressure.

3

Radioactive nuclei for β+γ PET and theranostics: selected candidates

88%

Matulewicz T.

Bio-Algorithms and Med-Systems

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2021

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tom Vol. 17, no. 4

235--239

EN

Positron emission tomography (PET) is an established medical diagnostic imaging method. Continuous improvements are aimed at refining image reconstruction, reducing the amount of radioactive tracer and combining with targeted therapy. Time-of-flight (TOF)-PET provides the localization of the tracer through improved time resolution, nuclear physics may contribute to this goal via selection of radioactive nuclei emitting additional γ-rays. This additional radiation, when properly detected, localizes the decay of the tracer at the line of response (LoR) determined by two detected 511 keV quanta. Selected candidates are presented. Some are particularly interesting, as they are strong candidates for theranostic applications.

4

Unparalleled and revolutionary impact of PET imaging on research and day to day practice of medicine

75%

Alavi A. , Werner T. J. , Stępień E. Ł. , Moskal P.

Bio-Algorithms and Med-Systems

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2021

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tom Vol. 17, no. 4

203--212

EN

Positron emission tomography (PET) imaging is the most quantitative modality for assessing disease activity at the molecular and cellular levels, and therefore, it allows monitoring its course and determining the efficacy of various therapeutic interventions. In this scientific communication, we describe the unparalleled and revolutionary impact of PET imaging on research and day to day practice of medicine. We emphasize the critical importance of the development and synthesis of novel radiotracers (starting from the enormous impact of F-Fluorodeouxyglucose (FDG) introduced by investigators at the University of Pennsylvania (PENN)) and PET instrumentation. These innovations have led to the total-body PET systems enabling dynamic and parametric molecular imaging of all organs in the body simultaneously. We also present our perspectives for future development of molecular imaging by multiphoton PET systems that will enable users to extract substantial information (owing to the evolving role of positronium imaging) about the related molecular and biological bases of various disorders, which are unachievable by the current PET imaging techniques.

5

Positronium as a biomarker of hypoxia

63%

Moskal P. , Stępień E. Ł.

Bio-Algorithms and Med-Systems

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2021

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tom Vol. 17, no. 4

311--319

EN

In this review article, we present arguments demonstrating that the advent of high sensitivity total-body PET systems and the invention of the method of positronium imaging, open realistic perspectives for the application of positronium as a biomarker for in-vivo assessment of the degree of hypoxia. Hypoxia is a state or condition, in which the availability of oxygen is not sufficient to support physiological processes in tissue and organs. Positronium is a metastable atom formed from electron and positron which is copiously produced in the intramolecular spaces in the living organisms undergoing positron emission tomography (PET). Properties of positronium, such as e.g., lifetime, depend on the size of intramolecular spaces and the concentration in them of oxygen molecules. Therefore, information on the partial pressure of oxygen (pO2) in the tissue may be derived from the positronium lifetime measurement. The partial pressure of oxygen differs between healthy and cancer tissues in the range from 10 to 50 mmHg. Such differences of pO2 result in the change of ortho-positronium lifetime e.g., in water by about 2–7 ps. Thus, the application of positronium as a biomarker of hypoxia requires the determination of the mean positronium lifetime with the resolution in the order of 2 ps. We argue that such resolution is in principle achievable for organ-wise positronium imaging with the total-body PET systems.

6

Image-Guided FLASH Proton Therapy. A dream? Naivety? Arrogance? Or a Necessity?

51%

Lang K.

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2024

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tom Vol. 20, Special issue

17--26

EN

Objective: The in-vivo therapy guidance by imaging and dosimetry of proton irradiations, generically known as proton range verification, are some of the most underinvested aspects of radiation oncology. They trail behind other advances in radiation therapy due to the scarcity of sensitive instruments compounded by the lack of treatment protocols for precision monitoring of effects of beam radiation. This is despite that such measurements may dramatically enhance the treatment accuracy and lower the postradiation toxicity, thus improving the entire outcome of cancer therapy. Methods: In this contribution, we focus on the motivation of designing and building of an in-beam time-of-flight (ToF) positron-emission-tomography (PET) scanner with the depth- -of-interaction (DoI) capability for high sensitivity and improved fidelity of imaging. A scanner could be augmented with a tungsten collimator that would enable prompt-gamma imaging (PGI) via single-photon emission computed tomography (SPECT) technique. Results: We present selected results of our pre-clinical experiments with a FLASH proton beam and discuss other related ideas towards improving and expanding the use of PET/PGI/SPECT detectors for proton therapy. A scanner provides an access to data during the spill and past the spill permitting to capture the beam interaction and kinetic monitoring of its effect thus allowing a thorough assessment of each irradiation. Conclusions: A novel scanner for multiple modalities can substantially improve the treatment precision of proton therapy leading to less toxic outcome of irradiations. Using it in the FLASH modality would additionally expand the patient reach of proton therapy.

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Toksykologia współczesna nanomateriałów magnetycznych

51%

Cywinska M. A. , Grudzinski I. P.

Roczniki Państwowego Zakładu Higieny

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2012

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tom 63

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nr 3

PL

Aktualny postęp w zakresie nanobiotechnologii doprowadził do rozwoju nowego obszaru nanomedycyny, związanego z aplikacją nano(bio)materiałów zarówno w celach diagnostycznych jak i terapeutycznych (teranostyki). Główne oczekiwania i wyzwania w powyższym zakresie dotyczą nanoproduktów magnetycznych, otrzymywanych metodami bioinżynierii, o potencjalnym zastosowaniu w transporcie leków, przede wszystkim leków przeciwnowotworowych, stosowanych w terapiach wykorzystujących określone molekularne punkty uchwytu. Wyjątkowe właściwości fizykochemiczne nanocząstek magnetycznych rokują nadzieję na rozwój współczesnej nanomedycyny nowotworów, stanowiąc między innymi technologiczny przełom w zakresie celowanego transportu leków i genów, terapii nowotworów z wykorzystaniem magnetycznej hipertermii, inżynierii tkankowej, znakowania komórek nowotworowych czy molekularnego obrazowania rezonansem magnetycznym. Wraz z szerokim zainteresowaniem magnetycznymi nanoproduktami bioinżynierii, w sferze szczególnej uwagi pozostaje ich potencjał toksyczny. Pokaźna ilość dotychczasowych dowodów naukowych sugeruje, że pewne właściwości nanocząstek magnetycznych (np. podwyższona aktywność powierzchniowa, zdolność do penetracji przez błony komórkowe, oporność na procesy biodegradacji) może zwiększać ich potencjał cytotoksyczny w porównaniu z odpowiadającymi im materiałami nieposiadającymi rozmiarów w nanoskali. Innymi słowy, ocena bezpieczeństwa przeprowadzona w odniesieniu do standardowych materiałów magnetycznych, może mieć ograniczone zastosowanie w ocenie ryzyka narażenia zdrowotnego i środowiskowego w przypadku nowych nanoproduktów magnetycznych otrzymanych metodami bioinżynierii. W niniejszym artykule dyskutujemy główne kierunki badawcze prowadzone w doświadczalnych modelach in vitro oraz in vivo w celu oceny toksyczności magnetycznych nanozwiązków, zwracając szczególną uwagę na problematykę analizy toksykologicznej nanomagnetyków. W pracy zaprezentowano ponadto nowe kierunki badawcze prowadzone na polu nanotoksykologii, podkreślając znaczenie rozwoju alternatywnych metod testowania magnetycznych nano(bio)produktów.

EN

Current advances in nanobiotechnology have led to the development of new field of nanomedicine, which includes many applications of nano(bio)materials for both diagnostic and therapeutic purposes (theranostics). Major expectations and challenges are on bioengineered magnetic nanoparticles when their come to delivering drug compounds, especially to targeting anticancer drugs to specific molecular endpoints in cancer therapy. The unique physicochemical properties of these nanoparticles offer great promise in modern cancer nanomedicine to provide new technological breakthroughs, such as guided drug and gene delivery, magnetic hyperthermia cancer therapy, tissue engineering, cancer cell tracking and molecular magnetic resonance imaging. Along with the expanding interest in bio-engineered magnetic nanoproducts their potential toxicity has become one of the major concerns. To date, a number of recent scientific evidences suggest that certain properties of magnetic nanoparticles (e.g., enhanced reactive area, ability to cross cell membranes, resistance to biodegradation) may amplify their cytotoxic potential relative to bulk non-nanoscale counterparts. In other words, safety assessment developed for ordinary magnetic materials may be of limited use in determining the health and environmental risks of the novel bio-engineered magnetic nanoproducts. In the present paper we discuss the main directions of research conducted to assess the toxicity of magnetic nanocompounds in experimental in vitro and in vivo models, pointing to the key issues concerning the toxicological analysis of magnetic nanomaterials. In addition new research directions of nanotoxicological studies elucidating the importance of developing alternative methods for testing magnetic nano(bio)products are also presented.