708 research outputs found

    Application of an artificial intelligence segmentation for deep hyperthermia treatment planning in the pelvic region

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    During a microwave hyperthermia oncology treatment, the target region temperature is elevated to the temperatures of 40–44 °C, which improves the therapeutic effect of a standard radiotherapy and/or chemotherapy treatments. Amplitudes and phases of antenna input signals in the phased array setup surrounding the 3D patient model are optimised with respect to maximise the energy deposition in the target region. In this study, we successfully integrated an automatic artificial intelligence segmentation routine, used for patient-specific 3D model generation, into the hyperthermia treatment planning process. This allows us to apply more realistic patient 3D model for the online hyperthermia guidance including detailed retrospective analyses of the overall treatment quality, possibly leading to a widespread clinical use of the hyperthermia treatment planning

    Application of virtual reality technology in simulation of automated workplaces

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    S pojavom visoko razlučive grafike, brzog računanja, te dobre interakcije uređaja s korisnikom, tehnologija virtualne stvarnosti (VS) u posljednjih nekoliko godina je jedna od glavnih tehnologija. Važan koncept koji predstavlja VS je sustav predočavanja, koji se odnosi na osjećaj potpune uronjenosti u trodimenzijskom računalno generiranom okruženju, pomoću koje se iz korisničke perspektive uvelike olakšava praćenje. Glavna prednost korištenja virtualne stvarnosti očituje se kao mogućnost stvaranja i simuliranja novih tehnoloških jedinica prije njihove realizacije. Ovo može doprinijeti povećanju sigurnosti, povećanju ergonomije i smanjenju troškova. Virtualni model radnog mjesta mogao bi otkriti skrivene pogreške koje se eliminiraju, a koje bi u kasnijoj fazi na tom radnom mjestu mogle uzrokovati velike poteškoće.With the advent of high-resolution graphics, high-speed computing, and user interaction devices, virtual reality (VR) has emerged as a major new technol­ogy in recent years. An important new concept introduced by many VR sys­tems is immersion, which refers to the feeling of complete immersion in a three-dimensional computer-generated environment by means of user-cen­tered perspective achieved through tracking the user. Main advantage of virtual reality application usage is the possibility of creation and simulation of new technological unit before its realization. This may contribute to increasing of safety and ergonomics and decreasing of economical aspects of new proposed unit. Virtual model of proposed workcell could reveal hidden errors whose elimination in later stage of the new workcell creation should cause great difficulties

    Thermal stability of Al-Cu-Fe quasicrystals prepared by SHS method

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    Quasicrystal-containing materials are usually prepared by rapid solidification of the melt (e.g. by melt spinning) or mechanical alloying. In this work, the method using exothermic reactions between compressed metallic powders called SHS (Self-propagating High-temperature Synthesis) was tested. The microstructure and phase composition of the product was described in dependence on cooling regime from the reaction temperature. Thermal stability of prepared Al-Cu-Fe quasicrystals was studied by annealing at the temperatures of 300 and 500 °C

    Model-Based Noninvasive Estimation of Intracranial Pressure from Cerebral Blood Flow Velocity and Arterial Pressure

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    Intracranial pressure (ICP) is affected in many neurological conditions. Clinical measurement of pressure on the brain currently requires placing a probe in the cerebrospinal fluid compartment, the brain tissue, or other intracranial space. This invasiveness limits the measurement to critically ill patients. Because ICP is also clinically important in conditions ranging from brain tumors and hydrocephalus to concussions, noninvasive determination of ICP would be desirable. Our model-based approach to continuous estimation and tracking of ICP uses routinely obtainable time-synchronized, noninvasive (or minimally invasive) measurements of peripheral arterial blood pressure and blood flow velocity in the middle cerebral artery (MCA), both at intra-heartbeat resolution. A physiological model of cerebrovascular dynamics provides mathematical constraints that relate the measured waveforms to ICP. Our algorithm produces patient-specific ICP estimates with no calibration or training. Using 35 hours of data from 37 patients with traumatic brain injury, we generated ICP estimates on 2665 nonoverlapping 60-beat data windows. Referenced against concurrently recorded invasive parenchymal ICP that varied over 100 millimeters of mercury (mmHg) across all records, our estimates achieved a mean error (bias) of 1.6 mmHg and SD of error (SDE) of 7.6 mmHg. For the 1673 data windows over 22 hours in which blood flow velocity recordings were available from both the left and the right MCA, averaging the resulting bilateral ICP estimates reduced the bias to 1.5 mmHg and SDE to 5.9 mmHg. This accuracy is already comparable to that of some invasive ICP measurement methods in current clinical use.National Institutes of Health (U.S.) (R01 EB001659)CIMIT: Center for Integration of Medicine and Innovative Technolog

    iP & OEIP - Cytokinin Micro Application Modulates Root Development with High Spatial Resolution

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    State-of-the-art technology based on organic electronics can be used as a flow-free delivery method for organic substances with high spatial resolution. Such highly targeted drug micro applications can be used in plant research for the regulation of physiological processes on tissue and cellular levels. Here, for the first time, an organic electronic ion pump (OEIP) is reported that can transport an isoprenoid-type cytokinin, N-6-isopentenyladenine (iP), to intact plants. Cytokinins (CKs) are plant hormones involved in many essential physiological processes, including primary root (PR) and lateral root (LR) development. Using the Arabidopsis thaliana root as a model system, efficient iP delivery is demonstrated with a biological output - cytokinin-related PR and LR growth inhibition. The spatial resolution of iP delivery, defined for the first time for an organic compound, is shown to be less than 1 mm, exclusively affecting the OEIP-targeted LR. Results from the application of the high-resolution OIEP treatment method confirm previously published findings showing that the influence of CKs may vary at different stages of LR development. Thus, OEIP-based technologies offer a novel, electronically controlled method for phytohormone delivery that could contribute to unraveling cytokinin functions during different developmental processes with high specificity

    Fluorescence-activated multi-organelle mapping of subcellular plant hormone distribution

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    Auxins and cytokinins are two major families of phytohormones that control most aspects of plant growth, development and plasticity. Their distribution in plants has been described, but the importance of cell- and subcellular-type specific phytohormone homeostasis remains undefined. Herein, we revealed auxin and cytokinin distribution maps showing their different organelle-specific allocations within the Arabidopsis plant cell. To do so, we have developed Fluorescence-Activated multi-Organelle Sorting (FAmOS), an innovative subcellular fractionation technique based on flow cytometric principles. FAmOS allows the simultaneous sorting of four differently labelled organelles based on their individual light scatter and fluorescence parameters while ensuring hormone metabolic stability. Our data showed different subcellular distribution of auxin and cytokinins, revealing the formation of phytohormone gradients that have been suggested by the subcellular localization of auxin and cytokinin transporters, receptors and metabolic enzymes. Both hormones showed enrichment in vacuoles, while cytokinins were also accumulated in the endoplasmic reticulum

    New polyene macrolide family produced by submerged culture of Streptomyces durmitorensis

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    A new polyene macrolide family, closely related to the pentaene macrolide antibiotic roflamycoin, was isolated from the both fermentation broth and biomass of Streptomyces durmitorensis wild-type strain MS405. The main compound was identified by NMR and Fourier transform ion cyclotron resonance mass spectrometry as 32,33-didehydroroflamycoin (1; DDHR). Additional four structurally related compounds were determined solely by MS analysis. DDHR induces cell death by apoptosis in various cancer cell lines as demonstrated by DNA fragmentation. Striking feature of DDHR is its internal fluorescence allowing visualization of labeled plasma membranes and internal membrane structures. The Journal of Antibiotics (2011) 64, 717-722; doi:10.1038/ja.2011.81; published online 14 September 201
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