Search results for "Radiofrequency"
showing 4 items of 94 documents
The Palliative Care in the Metastatic Spinal Tumors. A Systematic Review on the Radiotherapy and Surgical Perspective
2022
Spine represents the most common site for metastatic disease involvement. Due to the close relationship between the spinal cord and critical structures, therapeutic management of spinal metastases remains challenging. Spinal localization can lead to neurological sequelae, which can significantly affect the quality of life in patients with a limited life expectancy. The authors conducted a systematic literature review according to PRISMA guidelines in order to determine the impact of the most updated palliative care on spinal metastases. The initial literature search retrieved 2526 articles, manually screened based on detailed exclusion criteria. Finally, 65 studies met the inclusion criteri…
Radiofrequency and 2.45 GHz electron cyclotron resonance H− volume production ion sources
2016
The volume production of negative hydrogen ions (H-) in plasma ion sources is based on dissociative electron attachment (DEA)to rovibrationally excited hydrogen molecules(H2), which is a two-step process requiring both, hot electrons for ionization, and vibrational excitation of the H2 and cold electrons for the H- formation through DEA. Traditionally H- ion sources relying on the volume production have been tandem-type arc discharge sources equipped with biased filament cathodes sustaining the plasma by thermionic electron emission and with a magnetic filter separating the main discharge from the H- formation volume. The main motivation to develop ion sources based on radiofrequency (RF) o…
Pētījums par frekvences un elektroda materiāla ietekmi radiofrekvences ķirurģijā izmantojot cūkas ādas audus in vitro un in vivo
2016
Lai izvērtētu radiofrekvences ķirurģijas ietekmi incīziju veikšanai ādas audos, ir nepieciešams veikt pētījumus gan in vivo gan in vitro apstākļos. Ir nepieciešams izvērtēt dažādu frekvenču, elektrodu materiālu un griešanas ātruma ietekmi uz audiem veicot ķirurģisko operāciju. Latvijas Universitātes Medicīnas fakultātes Eksperimentālā Ķirurģijas centra vadībā, un sadarbībā ar MedTecResearch centru Vācijā, Krakovā un institūtu “Leibniz-Institute für Nutztierbiologie” Vācijā, Dummerstrofā tika veiktas incīzijas 12 laboratorijas cūku ādā sedācijas apstākļos. Brūču dzīšanas process tika izvērtēts sestajā un divpadsmitajā dienā pēc operācijas veikšanas. Tika salīdzināta termālā karstuma ietekme …
Multi-Chip RFID Antenna Integrating Shape-Memory Alloys for Detection of Thermal Thresholds
2011
Low-cost wireless measurement of objects' temperature is one of the greatest expectation of radiofrequency identification technology for the so many applications in cold supply-chain control and safety assessment in general. In this context, the paper proposes a dual-chip UHF tag embedding shape memory alloys (SMA) able to transform the variation of the tagged item's temperature into a permanent change of antenna radiation features. This event-driven antenna is hence able to selectively activate the embedded microchips according to the temperature above or below a given threshold. A general design methodology for the resulting two-ports tag antenna is here introduced and then applied to pro…