529 research outputs found

    Quantification of tumour heterogenity in MRI

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    Cancer is the leading cause of death that touches us all, either directly or indirectly. It is estimated that the number of newly diagnosed cases in the Netherlands will increase to 123,000 by the year 2020. General Dutch statistics are similar to those in the UK, i.e. over the last ten years, the age-standardised incidence rate1 has stabilised at around 355 females and 415 males per 100,000. Figure 1 shows the cancer incidence per gender. In the UK, the rise in lifetime risk of cancer is more than one in three and depends on many factors, including age, lifestyle and genetic makeup

    Sensitivity of standard and stacked RADFET dosimeters

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    Radiation Sensing Field Effect Transistors (RADFETs), also known as MOSFET dosimeters, are discrete p-channel MOSFETs with the gate oxide engineered for increased radiation sensitivity. RADFETs are small, require very little or no power during operation, read-out is simple and non-destructive, and their electronic signal is suitable for integration with the electronics systems. For these reasons RADFETs have found applications in quality assurance of radiotherapy, dose monitoring in high energy physics laboratories, accidental personal dosimetry, and space. Lower dose applications, such as e.g. occupational personal dosimetry and radiology, are currently out of reach owing to inherent sensitivity limits of the standard RADFET technology. Tyndall National Institute has been involved in RADFET research and development, fabrication, and commercialisation for several decades and has acquired significant experience in the technology and applications. This paper presents Tyndall recent efforts in RADFET manufacturing and characterisation for different applications and discusses possible approaches towards increased sensitivity of the technology, including standard and stacked RADFETs.Fourth International Conferenceon Radiation and Applications in Various Fields of Research, RAD 2016, May 23-27, 2016, Niš, Serbi

    Proceedings Virtual Imaging Trials in Medicine 2024

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    This submission comprises the proceedings of the 1st Virtual Imaging Trials in Medicine conference, organized by Duke University on April 22-24, 2024. The listed authors serve as the program directors for this conference. The VITM conference is a pioneering summit uniting experts from academia, industry and government in the fields of medical imaging and therapy to explore the transformative potential of in silico virtual trials and digital twins in revolutionizing healthcare. The proceedings are categorized by the respective days of the conference: Monday presentations, Tuesday presentations, Wednesday presentations, followed by the abstracts for the posters presented on Monday and Tuesday

    Interaction of some polyoxotunstates with acetylcholinesterase

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    Polyoxometalates (POMs) are polyanionic oligomeric aggregates of transition metal ions, such as tungsten, molybdenum, vanadium, etc. held together by oxygen bridges, with a high density of negative charge. They are relatively stable, some even highly stable in aqueous solutions at biological pH values. In addition to applications in catalysis, separations, analysis, and as electrondense imaging agents, some of these complexes have been shown to exhibit biological activity in vitro as well as in vivo ranging from anti-cancer, antibiotic, and antiviral to antidiabetic effects. Recent investigations reported some polyoxotungstates as reversible inhibitors of acetylcholinesterase (AChE), making them potential anti-Alzheimer’s drugs. AChE is a serine hydrolase mainly found at neuromuscular junctions and cholinergic brain synapses. Its principal biological role is the termination of impulse transmission at cholinergic synapses. Reversible inhibitors of AChE mostly have therapeutic applications, while toxic effects are associated with irreversible AChE activity modulators. Reversible inhibitors play an important role in the pharmacological manipulation of the enzyme activity, and have been applied in the diagnostic and/or treatment of various diseases such as: myasthenia gravis, AD, postoperative ileus, bladder distention, glaucoma, as well as antidote to anticholinergic overdose. The effect of four new synthesized polyoxotungstates soluble in water on AChE activity was studied. AChE is purified from electric eel and commercially available. The enzyme was treated in vitro with polyoxotungstates in the concentration range from 1 × 10-7 to 1 × 10-3 mol/L at 37ºC for 15 minutes, and the incubation time was 12 min. The obtained dependence remaining enzyme activity vs. the inhibitor concentration fitted the sigmoidal function. IC50values, indicating the enzyme sensitivity toward the inhibitor and the inhibitory capacity of the analyzed compounds, were determined from the inhibition sigmoidal curves. Na10[H2W12O42] × 27H2O did not markedly reduce AChE activity at the highest investigated concentration (1 mmol/L). K7[SiV3W9O40] × 10H2O exhibited a weak inhibitory potential, causing 50% decrease in the enzyme activity at 5 × 10-4 mol/L. However, AChE sensitivity in the presence of K7[Ti2PW10O40] was several hundred times higher, reaching IC50 at 1.15 × 10-6 mol/L. Furthermore, (NH4)14[NaP5W30O110] × 31H2O demonstrated the strongest capacity to inhibit AChE. In the presence of its low concentration of 2 × 10-8 mol/L, the enzyme activity was noticeably reduced related to the control value (obtained without inhibitor), while 50% decrease in AChE activity was achieved at 3.8 × 10-7 mol/L.Fourth International Conferenceon Radiation and Applications in Various Fields of Research, RAD 2016, May 23-27, 2016, Niš, Serbi

    Validation Method for Pesticide Residue after Gamma Irradiation

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    Pesticide residues include the remaining substances or mixtures, metabolites and impurities in food which are considered to be toxicological significance. The goal of this work was validation method for the determination of residue by UPLC PDA and GC MS techniques. Special scope has been chlorpyrifos from apple after oil and emulsion formulation Radar EW and Radar EC treatment. In order to fully respond to this task, it has been induced the degradation products of active component -chlorpyrifos from these formulations. The degradation products chlorpyrifosoxon, 3,5,6-trichloro-2-pyridinol (TCP) and o,o -diethyl thiophosphate (DTPA) received after gamma radiation samples in a permanent for 66 hours with 2,5 KGray from Co-60 source. Gamma radiation is the closest degradation to natural conditions, followed degradation path, based on the chemical and microbiological processes. Four different extraction procedures have been used: liquid-liquid extraction (Dutch procedure), solid phase extraction with HLB cartridge, multiwall carbon nano tubes and Quechers extraction. The recovery for these clean up methods has been in range 75-94%. The validation parameters for UPLC PDA has been: LOD 0,06 ppm, LOQ 0,18 ppm. The linearity was confirmed by correlation coefficient, R=0.998 for UPLC. The parameter for GC MS has been on ppm level also. The correlation coefficient for GC MS is 0.999. The result on apple samples showed that for pesticide residue quantifications is more adequate GC MS technique that is characterized by highest recovery, the lowest standard deviation and better LOQ.Fourth International Conferenceon Radiation and Applications in Various Fields of Research, RAD 2016, May 23-27, 2016, Niš, Serbi

    Biomedical Perspectives II

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    Abstract book of International Scientific Conference of Students, Postgraduates and Young Scientist

    EPID-based 3D dosimetry for pre-treatment IMRT/VMAT quality assurance

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    Creating the Future: Research and Technology

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    With the many different technical talents, Marshall Space Flight Center (MSFC) continues to be an important force behind many scientific breakthroughs. The MSFC's annual report reviews the technology developments, research in space and microgravity sciences, studies in space system concepts, and technology transfer. The technology development programs include development in: (1) space propulsion and fluid management, (2) structures and dynamics, (3) materials and processes and (4) avionics and optics
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