63 research outputs found

    Central μ+μ−\mu^{+}\mu^{-} production via photon-photon fusion in proton-proton collisions with proton dissociation

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    We present a formalism which uses fluxes of equivalent photons including transverse momenta of the intermediate photons. The formalism reminds the familiar ktk_t-factorization approach used, e.g., to study the two-photon production of ccˉc\bar{c} or bbˉb\bar{b} pairs. The results of the new method are compared with those obtained using the code LPAIR, and a good agreement is obtained. The inclusion of the photon transverse momenta is necessary in studies of correlation observables. We present distributions for the dimuon invariant mass, transverse momentum of the muon pair and relative azimuthal angle between muons separately for elastic-elastic, elastic-inelastic, inelastic-elastic and inelastic-inelastic mechanisms. For typical experimental cuts all mechanisms give similar contributions. The results are shown for different sets of cuts relevant for the LHC experiments. The cross sections in different regions of phase space depend on F2F_2 structure function in different regions of xx and Q2Q^2. A comment on F2F_2 is made.Comment: 24 pages, 36 figures, 2 table

    "Medical Student Syndrome"-A Myth or a Real Disease Entity? Cross-Sectional Study of Medical Students of the Medical University of Silesia in Katowice, Poland.

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    The description of Medical Student Syndrome is based on the assumption that inexperienced medical students are prone to develop a pathological fear of medical conditions they are taught about. The aim of this study is to examine the sample of students (medical and non-medical) in order to assess and compare their level of hypochondriacal attitudes and health-related anxiety. We also examined other factors which might have had an influence on hypochondria and nosophobia attitudes among students. Methods: The study was conducted in two groups of students: 313 medical students at the Medical University of Silesia and 293 students at non-medical universities in Katowice, Poland. The study used the medical student syndrome self-explanatory questionnaire constructed for the study, taking into account the specificity of the group and the research problem. The research questionnaire was completed in an online survey by 606 students. Results: The results of the study showed that medical students obtained the same scores on a nosophobic scale as the non-medical students (p = 0.5). The analysis of hypochondriacal behavior showed significantly higher results in the non-medical student group (p = 0.02). In the entire study group, females and participants with mental disorders obtained higher scores in relation to nosophobia. Symptoms of depression and anxiety were more common in the group of medical students. Conclusions: Medical studies are not a risk factor for the occurrence of health anxiety and hypochondrial attitudes. Such factors are female gender and having a mental illness

    From 2D to 3D Mixed Reality Human-Robot Interface in Hazardous Robotic Interventions with the Use of Redundant Mobile Manipulator

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    Part de la conferència: ICINCO 2021: 18th International Conference on Informatics in Control, Automation and Robotics (juliol 2021)3D Mixed Reality (MR) Human-Robot Interfaces (HRI) show promise for robotic operators to complete tasks more quickly, safely and with less training. The objective of this study is to assess the use of 3D MR HRI environment in comparison with a standard 2D Graphical User Interface (GUI) in order to control a redundant mobile manipulator. The experimental data was taken during operation with a 9 DOF manipulator mounted in a robotized train, CERN Train Inspection Monorail (TIM), used for the Beam Loss Monitor robotic measurement task in a complex hazardous intervention scenario at CERN. The efficiency and workload of an operator were compared with the use of both types of interfaces with NASA TLX method. The usage of heart rate and Galvanic Skin Response parameters for operator condition and stress monitoring was tested. The results show that teleoperation with 3D MR HRI mitigates cognitive fatigue and stress by improving the operators understanding of both the robot’s pose and the surr ounding environment or scene

    Biodegradable polymer-coated thin strut sirolimus- -eluting stent versus durable polymer-coated everolimus-eluting stent in the diabetic population

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    Background: The number of patients with diabetes mellitus (DM) presenting with coronary artery disease is increasing and accounts for more than 30% of patients undergoing percutaneous coronary interventions (PCI). The biodegradable polymer drug-eluting stents were developed to improve vascular healing. It was sought herein, to determine 1-year clinical follow-up in patients with DM treated with the thin strut biodegradable polymer-coated sirolimus-eluting stent (BP-SES) versus durable coating everolimus-eluting stent (DP-EES).Methods: Patients were retrospectively analyzed with DM were treated with either a BP-SES (ALEXâ„¢, Balton, Poland, n = 670) or a DP-EES (XIENCEâ„¢, Abbott, USA, n = 884) with available 1 year clinical follow-up using propensity score matching. Outcomes included target vessel revascularization (TVR) as efficacy outcome and all-cause death, myocardial infarction, and definite/probable stent thrombosis as safety outcomes.Results: After propensity score matching 527 patients treated with BP-SES and 527 patients treated with DP-EES were selected. Procedural and clinical characteristics were similar between both groups. In-hospital mortality was 3.23% in BP-SES vs. 2.09% in DP-EES group (p = 0.25). One-year followup demonstrated comparable efficacy outcome TVR (BP-SES 6.64% vs. DP-EES 5.88%; p = 0.611), as well as similar safety outcomes of all-cause death (BP-SES 10.06% vs. DP-EES 7.59%; p = 0.158), myocardial infarction (BP-SES 7.959% vs. DP-EES 6.83%; p = 0.813), and definite/probable stent thrombosis (BP-SES 1.14% vs. DP-EES 0.76%; p = 0.525).Conclusions: The thin-strut biodegradable polymer coated, sirolimus-eluting stent demonstrated comparable clinical outcomes at 1-year after implantation to DP-EES. These data support the relative safety and efficacy of BP-SES in diabetic patients undergoing PCI

    Brachial neuralgic amyotrophy, a rare disease with serious diagnostic problems - case report

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    Neuralgic amyotrophy(NA), is a rare and highly variable neurological disorder of unknown aetiology that causes serious diagnostic problems. We described a case of NA with atrophy of the brachialis muscle in order to enrich clinicians’ knowledge about this disorder and to help them in the proper diagnosis of NA. A 21-year-old man presented with sudden, severe pain in the right biceps muscle. The man had consultations with several doctors and physiotherapists. Three magnetic resonance imaging (MRI) examinations, a nerve conduction study (NCS) and needle electromyography (EMG) were performed. Only after 6 months, based on medical history, physical examination and ultrasound imaging (USI), the physiotherapist suggested NA, which was later on confirmed by a neurologist. This case description of NA showed a variety of symptoms that made it difficult to establish an accurate diagnosis for a longer period of time. The diagnostic procedure, as well as the prolonged time between the onset of symptoms and diagnosis, indicates the need for further education of clinicians to better understand the symptoms of NA

    Performance of a deep learning enhancement method applied to PET images acquired with a reduced acquisition time

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    Background: This study aims to evaluate the performance of a deep learning enhancement method in PET images reconstructed with a shorter acquisition time, and different reconstruction algorithms. The impact of the enhancement on clinical decisions was also assessed. Material and methods: Thirty-seven subjects underwent clinical whole-body [18F]FDG PET/CT exams with an acquisition time of 1.5 min per bed position. PET images were reconstructed with the OSEM algorithm using 66% counts (imitating 1 min/bed acquisition time) and 100% counts (1.5 min/bed). Images reconstructed from 66% counts were subsequently enhanced using the SubtlePET™ (SP) deep-learning-based software, (Subtle Medical, USA) — with two different software versions (SP1 and SP2). Additionally, images obtained with 66% counts were reconstructed with QClear™ (GE, USA) algorithm and enhanced with SP2. Volumes of interest (VOI) of the lesions and reference VOIs in the liver, brain, bladder, and mediastinum were drawn on OSEM images and copied on SP images. Quantitative SUVmax values per VOI of OSEM or QClear™ and AI-enhanced ‘shortened’ acquisitions were compared. Results: Two hundred and fifty-two VOIs were identified (37 for each reference region, and 104 for the lesions) for OSEM, SP1, SP2, and QClear™ images AI-enhanced with SP2. SUVmax values on SP1 images were lower than standard OSEM, but on SP2 differences were smaller (average difference for SP1 11.6%, for SP2 −4.5%). For images reconstructed with QClear™, SUVmax values were higher (average +8.9%, median 6.1%, SD 18.9%). For small lesions with SUVmax values range 2.0 to 4.0 decrease of measured SUVmax was much less significant with SP2 (for liver average −6.5%, median −5.6% for lesions average −5.6%, median — 6.0, SD 5.2%) and showed the best correlation with original OSEM. While no artifacts and good general diagnostic confidence were found in AI-enhanced images, SP1, the images were not equal to the original OSEM — some lesions were hard to spot. SP2 produced images with almost the same quality as the original 1.5 min/bed OSEM reconstruction. Conclusions: The studied deep learning enhancement method can be used to accelerate PET acquisitions without compromising quantitative SUVmax values. AI-based algorithms can enhance the image quality of accelerated PET acquisitions, enabling the dose reduction to the patients and improving the cost-effectiveness of PET/CT imaging

    Risk assessment of COVID-19 epidemic resurgence in relation to SARS-CoV-2 variants and vaccination passes

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    The introduction of COVID-19 vaccination passes (VPs) by many countries coincided with the Delta variant fast becoming dominant across Europe. A thorough assessment of their impact on epidemic dynamics is still lacking. Here, we propose the VAP-SIRS model that considers possibly lower restrictions for the VP holders than for the rest of the population, imperfect vaccination effectiveness against infection, rates of (re-)vaccination and waning immunity, fraction of never-vaccinated, and the increased transmissibility of the Delta variant. Some predicted epidemic scenarios for realistic parameter values yield new COVID-19 infection waves within two years, and high daily case numbers in the endemic state, even without introducing VPs and granting more freedom to their holders. Still, suitable adaptive policies can avoid unfavorable outcomes. While VP holders could initially be allowed more freedom, the lack of full vaccine effectiveness and increased transmissibility will require accelerated (re-)vaccination, wide-spread immunity surveillance, and/or minimal long-term common restrictions
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