80 research outputs found
Proton and carbon-ion minibeam therapy: from modeling to treatment
Arrays of minibeams of protons and C in tissue-like media were modeled
with Geant4 toolkit. A set of beam energies was used in simulations to provide
a Spead-out Bragg peak (SOBP) extended by 6 cm in depth for protons as well as
for C. In both cases, beams of 0.3 mm or 0.5 mm FWHM were arranged at
the entrance to a water phantom either on a rectangular or an hexagonal grid to
compare two kinds of projectiles and different minibeam patterns. Differential
and cumulative dose-volume histograms (DVH) were calculated and compared for
protons and C as dose uniformity metrics. A uniform dose distribution
was easily achieved with protons due to an enhanced lateral scattering of these
projectiles in comparison to C. The cumulative DVHs calculated for 0.3
mm or 0.5 mm minibeams almost coincide in the target volume, but diverge for
different grid patterns. In contrast, cumulative entry DVHs were found similar
for both grid patterns, but different for 0.3 mm and 0.5 mm minibeams.Comment: 8 pages, 5 figures, talk given at the XXV International Baldin
Seminar on High Energy Physics Problems "Relativistic Nuclear Physics and
Quantum Chromodynamics", September 18-23, 2023, Dubna, Russi
Development of High Granulated Straw Chambers of Large Sizes
We have developed the baseline design for the straw drift tube tracking
detectors for high rate environment application. The low-mass inner straw
elements and the technology of the multianode straws assembly was devised and
checked. The prototype chamber was constructed and studied the granularity of
similar chambers can be reduced to one cm2.
Submitted to Physics of Elementary Particles and Atomic Nuclei, LettersComment: 6 pages, 10 figure
On detection of narrow angle e+e- pairs from dark photon decays
A class of models of dark sectors consider new very weak interaction between
the ordinary and dark matter transmitted by U'(1) gauge bosons A' (dark
photons) mixing with our photons. If such A's exist, they could be searched for
in a light-shining-through-a-wall experiment with a high energy electron beam
from the CERN SPS. The proposed search scheme suggests detection of the e+e-
pairs produced in the A' -> e+e- decay with a very small opening angle.
Coordinate chambers based on the thin-wall drift tubes with a minimal material
budget and a two-hit resolution for e+ and e- tracks separated by more than 0.5
mm are considered as an option for detecting such pairs
Efficacy of Angio-Seal Device for Primary And Complicated Haemostasis: a Multicentre Retrospective Assay
Background. Femoral approach in endovascular surgery remains relevant being, however, associated with the risk of fatal and nonfatal complications. Modern techniques for instrumental haemostasis achieved with the AngioSeal device (Terumo Corporation, Japan) provide an opportunity to reduce the number of fatal and nonfatal complications. Aim. A multicentre assay of the efficacy and safety of instrumental puncture closure using AngioSeal devices (Terumo Corporation, Japan) in various settings and clinical situations.Materials and methods. A multicentre retrospective analysis of 1088 use cases of the AngioSeal device (Terumo Corporation, Japan) for “primary” and “complicated” instrumental haemostasis after femoral access has been conducted for the years 2018–2020. The mean patient age was 62.3 ± 11.6 years, including 845 men (78.0%) and 243 women (22.0%). Five centres for routine and emergency endovascular radiology participated in the study.Results. The AngioSeal device (Terumo Corporation, Japan) demonstrated a high method efficiency, with a 97.0% success rate of “primary” instrumental haemostasis (1055 of 1088 total successful haemostatic procedures) in various clinical settings. Arterial thrombosis at the approach side had a 3.0% complication rate (5 of 33 observations), all other complication types associated with haemorrhagic events (8 cases) or device malfunction and damage (20 cases).Discussion. The assay conducted suggests that the incidence of “complicated” instrumental haemostasis relates to technical drawbacks of the device application that required advance planning. The key identified prerequisites for a successful AngioSeal application (Terumo Corporation, Japan) are the alignment of anchor tubedelivery through soft tissue into the vessel lumen and its positioning inside the vessel.Conclusion. The constructive features and instrumental haemostatic technique realised in the AngioSeal device (Terumo Corporation, Japan) enable an effective and safe primary sealing of arterial puncture site in 97% cases
Medical workers of health care institutions as a risk group for chemo-resistant tuberculosis: analysis of incidence, a clinical case.
The purpose of our study was to analyze the prevalence of morbidity of medical workers of health care institutions and anti-tuberculosis institutions, as well as the analysis of resistance of mycobacterium tuberculosis strains among medical personal of health facilities in the Dnipropetrovsk region. Retrospective analysis for 2015 - 2017 of electronic database of the patients register (TB-manager), outpatient cards and case histories of patients which underwent treatment in pulmonary-tuberculosis and surgical departments of CI «DnepropetrovskRegional Clinical Treatment and Prophylactic Association "Phthisiology"» DRC» was conducted . The incidence of tuberculosis among medical workers in health care institutions of Ukraine remains at a fairly high, stable level (426 cases of tuberculosis in 2016, 389 cases in 2017) on the background of the decrease in the incidence among the general population (59.5 people per 100 thousand population in 2014 and 51.9 per 100 thousand population in 2017 ). In Ukraine among tuberculosis patients – medical workers, the overwhelming majority are workers of establishments of the general medical network (GMN) - 351 people, while in anti-tuberculosis institutions (ATI) in 2017, 38 cases of tuberculosis were registered. The article presents the clinical case of multidrug-resistant tuberculosis (MDR) in staff member of the pathoanatomical bureau, one of the medical institutions of the city Dnipro
Medical workers of health care institutions as a risk group for chemo-resistant tuberculosis: analysis of incidence, a clinical case.
The purpose of our study was to analyze the prevalence of morbidity of medical workers of health care institutions and anti-tuberculosis institutions, as well as the analysis of resistance of mycobacterium tuberculosis strains among medical personal of health facilities in the Dnipropetrovsk region. Retrospective analysis for 2015 - 2017 of electronic database of the patients register (TB-manager), outpatient cards and case histories of patients which underwent treatment in pulmonary-tuberculosis and surgical departments of CI «DnepropetrovskRegional Clinical Treatment and Prophylactic Association "Phthisiology"» DRC» was conducted . The incidence of tuberculosis among medical workers in health care institutions of Ukraine remains at a fairly high, stable level (426 cases of tuberculosis in 2016, 389 cases in 2017) on the background of the decrease in the incidence among the general population (59.5 people per 100 thousand population in 2014 and 51.9 per 100 thousand population in 2017 ). In Ukraine among tuberculosis patients – medical workers, the overwhelming majority are workers of establishments of the general medical network (GMN) - 351 people, while in anti-tuberculosis institutions (ATI) in 2017, 38 cases of tuberculosis were registered. The article presents the clinical case of multidrug-resistant tuberculosis (MDR) in staff member of the pathoanatomical bureau, one of the medical institutions of the city Dnipro
Многоцентровой ретроспективный анализ использования устройства «Angioseal» для осуществления первичного и осложненного гемостаза
Background. Femoral approach in endovascular surgery remains relevant being, however, associated with the risk of fatal and nonfatal complications. Modern techniques for instrumental haemostasis achieved with the AngioSeal device (Terumo Corporation, Japan) provide an opportunity to reduce the number of fatal and nonfatal complications. Aim. A multicentre assay of the efficacy and safety of instrumental puncture closure using AngioSeal devices (Terumo Corporation, Japan) in various settings and clinical situations.Materials and methods. A multicentre retrospective analysis of 1088 use cases of the AngioSeal device (Terumo Corporation, Japan) for “primary” and “complicated” instrumental haemostasis after femoral access has been conducted for the years 2018–2020. The mean patient age was 62.3 ± 11.6 years, including 845 men (78.0%) and 243 women (22.0%). Five centres for routine and emergency endovascular radiology participated in the study.Results. The AngioSeal device (Terumo Corporation, Japan) demonstrated a high method efficiency, with a 97.0% success rate of “primary” instrumental haemostasis (1055 of 1088 total successful haemostatic procedures) in various clinical settings. Arterial thrombosis at the approach side had a 3.0% complication rate (5 of 33 observations), all other complication types associated with haemorrhagic events (8 cases) or device malfunction and damage (20 cases).Discussion. The assay conducted suggests that the incidence of “complicated” instrumental haemostasis relates to technical drawbacks of the device application that required advance planning. The key identified prerequisites for a successful AngioSeal application (Terumo Corporation, Japan) are the alignment of anchor tubedelivery through soft tissue into the vessel lumen and its positioning inside the vessel.Conclusion. The constructive features and instrumental haemostatic technique realised in the AngioSeal device (Terumo Corporation, Japan) enable an effective and safe primary sealing of arterial puncture site in 97% cases.Введение. Бедренный доступ для эндоваскулярных операций сохраняет свою актуальность, однако его выполнение связано с риском возникновения фатальных и нефатальных осложнений. Современные технологии аппаратного гемостаза, достигаемого с помощью устройства «Angioseal» («Terumo Corporation», Япония), предоставляют возможность снижения числа фатальных и нефатальных осложнений. Цель исследования. Провести многоцентровую оценку эффективности и безопасности аппаратного закрытия пункционного отверстия с применением устройств «Angioseal» в различных условиях и клинических ситуациях.Материалы и методы. Проведен многоцентровой ретроспективный анализ 1088 случаев использования устройства «Angioseal» для осуществления «первичного» и «осложненного» аппаратного гемостаза после бедренного доступа в период с 2018 по 2020 год. Средний возраст пациентов составил 62,3 ± 11,6 года. Мужчин было 845 (78,0 %), женщин — 243 (22,0 %). В исследовании приняли участие пять центров, осуществляющих плановую и экстренную рентгенэндоваскулярную помощь.Результаты. Применение устройства «Angioseal» показывает высокую эффективность метода — 97,0 % успеха «первичного» аппаратного гемостаза (1055 случаев из 1088 успешных процедур гемостаза) в условиях различных клинических ситуаций. В структуре осложнений (3,0 %) — тромбоз артерий на стороне доступа составил 5 случаев из 33 наблюдений; остальные варианты осложнений были связаны с геморрагическими событиями (8 случаев) или отказом/повреждением устройства, наблюдаемым в 20 случаях.Обсуждение. По данным проведенного исследования мы заключили, что случаи «осложненного» аппаратного гемостаза были сопряжены с техническими трудностями применения устройства и требовали заблаговременного планирования. Ключевыми моментами успешного применения устройства «Angioseal» можно считать прямолинейность прохождения якоря устройства по доставляющей трубке через мягкие ткани в просвет сосуда и контроль расположения якоря в сосуде.Заключение. Конструктивные особенности и методика аппаратного гемостаза с применением устройства «Angioseal» в 97 % случаев позволяют эффективно и безопасно осуществлять первичное закрытие пункционного артериального доступа
The ATLAS Transition Radiation Tracker (TRT) proportional drift tube: design and performance
A straw proportional counter is the basic element of the ATLAS Transition Radiation Tracker (TRT). Its detailed properties as well as the main properties of a few TRT operating gas mixtures are described. Particular attention is paid to straw tube performance in high radiation conditions and to its operational stability
The ATLAS TRT electronics
The ATLAS inner detector consists of three sub-systems: the pixel detector spanning the radius range 4cm-20cm, the semiconductor tracker at radii from 30 to 52 cm, and the transition radiation tracker (TRT), tracking from 56 to 107 cm. The TRT provides a combination of continuous tracking with many projective measurements based on individual drift tubes (or straws) and of electron identification based on transition radiation from fibres or foils interleaved between the straws themselves. This paper describes the on and off detector electronics for the TRT as well as the TRT portion of the data acquisition (DAQ) system
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