38 research outputs found

    Modelling the behaviour of microbulk Micromegas in Xenon/trimethylamine gas

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    We model the response of a state of the art micro-hole single-stage charge amplication device (`microbulk' Micromegas) in a gaseous atmosphere consisting of Xenon/trimethylamine at various concentrations and pressures. The amplifying structure, made with photo-lithographic techniques similar to those followed in the fabrication of gas electron multipliers (GEMs), consisted of a 100 um-side equilateral-triangle pattern with 50 um-diameter holes placed at its vertexes. Once the primary electrons are guided into the holes by virtue of an optimized field configuration, avalanches develop along the 50 um-height channels etched out of the original doubly copper-clad polyimide foil. In order to properly account for the strong field gradients at the holes' entrance as well as for the fluctuations of the avalanche process (that ultimately determine the achievable energy resolution), we abandoned the hydrodynamic framework, resorting to a purely microscopic description of the electron trajectories as obtained from elementary cross-sections. We show that achieving a satisfactory description needs additional assumptions about atom-molecule (Penning) transfer reactions and charge recombination to be made

    Ultra low background Micromegas detectors for BabyIAXO solar axion search

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    The International AXion Observatory (IAXO) is a large scale axion helioscope that will look for axions and axion-like particles produced in the Sun with unprecedented sensitivity. BabyIAXO is an intermediate experimental stage that will be hosted at DESY (Germany) and that will test all IAXO subsystems serving as a prototype for IAXO but at the same time as a fully-fledged helioscope with potential for discovery. One of the crucial components of the project is the ultra-low background X-ray detectors that will image the X-ray photons produced by axion conversion in the experiment. The baseline detection technology for this purpose are Micromegas (Microbulk) detectors. We will show the quest and the strategy to attain the very challenging levels of background targeted for BabyIAXO that need a multi-approach strategy coming from ground measurements, screening campaigns of components of the detector, underground measurements, background models, in-situ background measurements as well as powerful rejection algorithms. First results from the commissioning of the BabyIAXO prototype will be shown.Comment: 4 pages, 2 figures, submitted for the proceedings of the International Conference on Micro Pattern Gaseous Detectors, December 2022, Israe

    Determinants of enhanced vulnerability to COVID-19 in UK cancer patients: a European Study

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    Background: Despite high contagiousness and rapid spread, SARS-CoV-2 has led to heterogeneous outcomes across affected nations. Within Europe, the United Kingdom (UK) is the most severely affected country, with a death toll in excess of 100.000 as of January 2021. We aimed to compare the national impact of COVID-19 on the risk of death in UK cancer patients versus those in continental Europe (EU). / Methods: We performed a retrospective analysis of the OnCovid study database, a European registry of cancer patients consecutively diagnosed with COVID-19 in 27 centres from February 27 to September 10, 2020. We analysed case fatality rates and risk of death at 30 days and 6 months stratified by region of origin (UK versus EU). We compared patient characteristics at baseline, including oncological and COVID-19 specific therapy across UK and EU cohorts and evaluated the association of these factors with the risk adverse outcome in multivariable Cox regression models. / Findings: Compared to EU (n=924), UK patients (n=468) were characterised by higher case fatality rates (40.38% versus 26.5%, p<0.0001), higher risk of death at 30 days (hazard ratio, HR 1.64 [95%CI 1.36-1.99]) and 6 months after COVID-19 diagnosis (47.64% versus 33.33%, p<0.0001, HR 1.59 [95%CI 1.33-1.88]). UK patients were more often males, of older age and more co-morbid than EU counterparts (p<0.01). Receipt of anticancer therapy was lower in UK versus EU patients (p<0.001). Despite equal proportions of complicated COVID-19, rates of intensive care admission and use of mechanical ventilation, UK cancer patients were less likely to receive anti-COVID-19 therapies including corticosteroids, anti-virals and interleukin-6 antagonists (p<0.0001). Multivariable analyses adjusted for imbalanced prognostic factors confirmed the UK cohort to be characterised by worse risk of death at 30 days and 6 months, independent of patient’s age, gender, tumour stage and status, number of co-morbidities, COVID-19 severity, receipt of anticancer and anti-COVID-19 therapy. Rates of permanent cessation of anticancer therapy post COVID-19 were similar in UK versus EU. / Interpretation: UK cancer patients have been more severely impacted by the unfolding of the COVID-19 pandemic despite societal risk mitigation factors and rapid deferral of anticancer therapy. The increased frailty of UK cancer patients highlights high-risk groups that should be prioritised for anti-SARS-CoV-2 vaccination. Continued evaluation of long-term outcomes is warranted

    SARS-CoV-2 omicron (B.1.1.529)-related COVID-19 sequelae in vaccinated and unvaccinated patients with cancer: results from the OnCovid registry

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    BACKGROUND: COVID-19 sequelae can affect about 15% of patients with cancer who survive the acute phase of SARS-CoV-2 infection and can substantially impair their survival and continuity of oncological care. We aimed to investigate whether previous immunisation affects long-term sequelae in the context of evolving variants of concern of SARS-CoV-2. METHODS: OnCovid is an active registry that includes patients aged 18 years or older from 37 institutions across Belgium, France, Germany, Italy, Spain, and the UK with a laboratory-confirmed diagnosis of COVID-19 and a history of solid or haematological malignancy, either active or in remission, followed up from COVID-19 diagnosis until death. We evaluated the prevalence of COVID-19 sequelae in patients who survived COVID-19 and underwent a formal clinical reassessment, categorising infection according to the date of diagnosis as the omicron (B.1.1.529) phase from Dec 15, 2021, to Jan 31, 2022; the alpha (B.1.1.7)-delta (B.1.617.2) phase from Dec 1, 2020, to Dec 14, 2021; and the pre-vaccination phase from Feb 27 to Nov 30, 2020. The prevalence of overall COVID-19 sequelae was compared according to SARS-CoV-2 immunisation status and in relation to post-COVID-19 survival and resumption of systemic anticancer therapy. This study is registered with ClinicalTrials.gov, NCT04393974. FINDINGS: At the follow-up update on June 20, 2022, 1909 eligible patients, evaluated after a median of 39 days (IQR 24-68) from COVID-19 diagnosis, were included (964 [50·7%] of 1902 patients with sex data were female and 938 [49·3%] were male). Overall, 317 (16·6%; 95% CI 14·8-18·5) of 1909 patients had at least one sequela from COVID-19 at the first oncological reassessment. The prevalence of COVID-19 sequelae was highest in the pre-vaccination phase (191 [19·1%; 95% CI 16·4-22·0] of 1000 patients). The prevalence was similar in the alpha-delta phase (110 [16·8%; 13·8-20·3] of 653 patients, p=0·24), but significantly lower in the omicron phase (16 [6·2%; 3·5-10·2] of 256 patients, p<0·0001). In the alpha-delta phase, 84 (18·3%; 95% CI 14·6-22·7) of 458 unvaccinated patients and three (9·4%; 1·9-27·3) of 32 unvaccinated patients in the omicron phase had sequelae. Patients who received a booster and those who received two vaccine doses had a significantly lower prevalence of overall COVID-19 sequelae than unvaccinated or partially vaccinated patients (ten [7·4%; 95% CI 3·5-13·5] of 136 boosted patients, 18 [9·8%; 5·8-15·5] of 183 patients who had two vaccine doses vs 277 [18·5%; 16·5-20·9] of 1489 unvaccinated patients, p=0·0001), respiratory sequelae (six [4·4%; 1·6-9·6], 11 [6·0%; 3·0-10·7] vs 148 [9·9%; 8·4-11·6], p=0·030), and prolonged fatigue (three [2·2%; 0·1-6·4], ten [5·4%; 2·6-10·0] vs 115 [7·7%; 6·3-9·3], p=0·037). INTERPRETATION: Unvaccinated patients with cancer remain highly vulnerable to COVID-19 sequelae irrespective of viral strain. This study confirms the role of previous SARS-CoV-2 immunisation as an effective measure to protect patients from COVID-19 sequelae, disruption of therapy, and ensuing mortality. FUNDING: UK National Institute for Health and Care Research Imperial Biomedical Research Centre and the Cancer Treatment and Research Trust

    Readout technologies for directional WIMP Dark Matter detection

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    The measurement of the direction of WIMP-induced nuclear recoils is a compelling but technologically challenging strategy to provide an unambiguous signature of the detection of Galactic dark matter. Most directional detectors aim to reconstruct the dark-matter-induced nuclear recoil tracks, either in gas or solid targets. The main challenge with directional detection is the need for high spatial resolution over large volumes, which puts strong requirements on the readout technologies. In this paper we review the various detector readout technologies used by directional detectors. In particular, we summarize the challenges, advantages and drawbacks of each approach, and discuss future prospects for these technologies

    Specialist palliative and end-of-life care for patients with cancer and SARS-CoV-2 infection: a European perspective

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    Background: Specialist palliative care team (SPCT) involvement has been shown to improve symptom control and end-of-life care for patients with cancer, but little is known as to how these have been impacted by the COVID-19 pandemic. Here, we report SPCT involvement during the first wave of the pandemic and compare outcomes for patients with cancer who received and did not receive SPCT input from multiple European cancer centres. Methods: From the OnCovid repository (N = 1318), we analysed cancer patients aged ⩾18 diagnosed with COVID-19 between 26 February and 22 June 2020 who had complete specialist palliative care team data (SPCT+ referred; SPCT− not referred). Results: Of 555 eligible patients, 317 were male (57.1%), with a median age of 70 years (IQR 20). At COVID-19 diagnosis, 44.7% were on anti-cancer therapy and 53.3% had ⩾1 co-morbidity. Two hundred and six patients received SPCT input for symptom control (80.1%), psychological support (54.4%) and/or advance care planning (51%). SPCT+ patients had more ‘Do not attempt cardio-pulmonary resuscitation’ orders completed prior to (12.6% versus 3.7%) and during admission (50% versus 22.1%, p < 0.001), with more SPCT+ patients deemed suitable for treatment escalation (50% versus 22.1%, p < 0.001). SPCT involvement was associated with higher discharge rates from hospital for end-of-life care (9.7% versus 0%, p < 0.001). End-of-life anticipatory prescribing was higher in SPCT+ patients, with opioids (96.3% versus 47.1%) and benzodiazepines (82.9% versus 41.2%) being used frequently for symptom control. Conclusion: SPCT referral facilitated symptom control, emergency care and discharge planning, as well as high rates of referral for psychological support than previously reported. Our study highlighted the critical need of SPCTs for patients with cancer during the pandemic and should inform service planning for this population

    Outcomes of the SARS-CoV-2 omicron (B.1.1.529) variant outbreak among vaccinated and unvaccinated patients with cancer in Europe: results from the retrospective, multicentre, OnCovid registry study

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    BACKGROUND: The omicron (B.1.1.529) variant of SARS-CoV-2 is highly transmissible and escapes vaccine-induced immunity. We aimed to describe outcomes due to COVID-19 during the omicron outbreak compared with the prevaccination period and alpha (B.1.1.7) and delta (B.1.617.2) waves in patients with cancer in Europe. METHODS: In this retrospective analysis of the multicentre OnCovid Registry study, we recruited patients aged 18 years or older with laboratory-confirmed diagnosis of SARS-CoV-2, who had a history of solid or haematological malignancy that was either active or in remission. Patient were recruited from 37 oncology centres from UK, Italy, Spain, France, Belgium, and Germany. Participants were followed up from COVID-19 diagnosis until death or loss to follow-up, while being treated as per standard of care. For this analysis, we excluded data from centres that did not actively enter new data after March 1, 2021 (in France, Germany, and Belgium). We compared measures of COVID-19 morbidity, which were complications from COVID-19, hospitalisation due to COVID-19, and requirement of supplemental oxygen and COVID-19-specific therapies, and COVID-19 mortality across three time periods designated as the prevaccination (Feb 27 to Nov 30, 2020), alpha-delta (Dec 1, 2020, to Dec 14, 2021), and omicron (Dec 15, 2021, to Jan 31, 2022) phases. We assessed all-cause case-fatality rates at 14 days and 28 days after diagnosis of COVID-19 overall and in unvaccinated and fully vaccinated patients and in those who received a booster dose, after adjusting for country of origin, sex, age, comorbidities, tumour type, stage, and status, and receipt of systemic anti-cancer therapy. This study is registered with ClinicalTrials.gov, NCT04393974, and is ongoing. FINDINGS: As of Feb 4, 2022 (database lock), the registry included 3820 patients who had been diagnosed with COVID-19 between Feb 27, 2020, and Jan 31, 2022. 3473 patients were eligible for inclusion (1640 [47·4%] were women and 1822 [52·6%] were men, with a median age of 68 years [IQR 57–77]). 2033 (58·5%) of 3473 were diagnosed during the prevaccination phase, 1075 (31·0%) during the alpha-delta phase, and 365 (10·5%) during the omicron phase. Among patients diagnosed during the omicron phase, 113 (33·3%) of 339 were fully vaccinated and 165 (48·7%) were boosted, whereas among those diagnosed during the alpha-delta phase, 152 (16·6%) of 915 were fully vaccinated and 21 (2·3%) were boosted. Compared with patients diagnosed during the prevaccination period, those who were diagnosed during the omicron phase had lower case-fatality rates at 14 days (adjusted odds ratio [OR] 0·32 [95% CI 0·19–0·61) and 28 days (0·34 [0·16–0·79]), complications due to COVID-19 (0·26 [0·17–0·46]), and hospitalisation due to COVID-19 (0·17 [0·09–0·32]), and had less requirements for COVID-19-specific therapy (0·22 [0·15–0·34]) and oxygen therapy (0·24 [0·14–0·43]) than did those diagnosed during the alpha-delta phase. Unvaccinated patients diagnosed during the omicron phase had similar crude case-fatality rates at 14 days (ten [25%] of 40 patients vs 114 [17%] of 656) and at 28 days (11 [27%] of 40 vs 184 [28%] of 656) and similar rates of hospitalisation due to COVID-19 (18 [43%] of 42 vs 266 [41%] of 652) and complications from COVID-19 (13 [31%] of 42 vs 237 [36%] of 659) as those diagnosed during the alpha-delta phase. INTERPRETATION: Despite time-dependent improvements in outcomes reported in the omicron phase compared with the earlier phases of the pandemic, patients with cancer remain highly susceptible to SARS-CoV-2 if they are not vaccinated against SARS-CoV-2. Our findings support universal vaccination of patients with cancer as a protective measure against morbidity and mortality from COVID-19. FUNDING: National Institute for Health and Care Research Imperial Biomedical Research Centre and the Cancer Treatment and Research Trust

    Physics potential of the International Axion Observatory (IAXO)

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    We review the physics potential of a next generation search for solar axions:the International Axion Observatory (IAXO). Endowed with a sensitivity todiscover axion-like particles (ALPs) with a coupling to photons as small asgaγ1012g_{a\gamma}\sim 10^{-12} GeV1^{-1}, or to electrons gaeg_{ae}\sim1013^{-13},IAXO has the potential to find the QCD axion in the 1 meV\sim1 eV mass rangewhere it solves the strong CP problem, can account for the cold dark matter ofthe Universe and be responsible for the anomalous cooling observed in a numberof stellar systems. At the same time, IAXO will have enough sensitivity todetect lower mass axions invoked to explain: 1) the origin of the anomalous"transparency" of the Universe to gamma-rays, 2) the observed soft X-ray excessfrom galaxy clusters or 3) some inflationary models. In addition, we reviewstring theory axions with parameters accessible by IAXO and discuss theirpotential role in cosmology as Dark Matter and Dark Radiation as well as theirconnections to the above mentioned conundrums

    Prevalence and impact of COVID-19 sequelae on treatment and survival of patients with cancer who recovered from SARS-CoV-2 infection: evidence from the OnCovid retrospective, multicentre registry study

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    Background: The medium-term and long-term impact of COVID-19 in patients with cancer is not yet known. In this study, we aimed to describe the prevalence of COVID-19 sequelae and their impact on the survival of patients with cancer. We also aimed to describe patterns of resumption and modifications of systemic anti-cancer therapy following recovery from SARS-CoV-2 infection. Methods: OnCovid is an active European registry study enrolling consecutive patients aged 18 years or older with a history of solid or haematological malignancy and who had a diagnosis of RT-PCR confirmed SARS-CoV-2 infection. For this retrospective study, patients were enrolled from 35 institutions across Belgium, France, Germany, Italy, Spain, and the UK. Patients who were diagnosed with SARS-CoV-2 infection between Feb 27, 2020, and Feb 14, 2021, and entered into the registry at the point of data lock (March 1, 2021), were eligible for analysis. The present analysis was focused on COVID-19 survivors who underwent clinical reassessment at each participating institution. We documented prevalence of COVID-19 sequelae and described factors associated with their development and their association with post-COVID-19 survival, which was defined as the interval from post-COVID-19 reassessment to the patients’ death or last follow-up. We also evaluated resumption of systemic anti-cancer therapy in patients treated within 4 weeks of COVID-19 diagnosis. The OnCovid study is registered in ClinicalTrials.gov, NCT04393974. Findings: 2795 patients diagnosed with SARS-CoV-2 infection between Feb 27, 2020, and Feb 14, 2021, were entered into the study by the time of the data lock on March 1, 2021. After the exclusion of ineligible patients, the final study population consisted of 2634 patients. 1557 COVID-19 survivors underwent a formal clinical reassessment after a median of 22·1 months (IQR 8·4–57·8) from cancer diagnosis and 44 days (28–329) from COVID-19 diagnosis. 234 (15·0%) patients reported COVID-19 sequelae, including respiratory symptoms (116 [49·6%]) and residual fatigue (96 [41·0%]). Sequelae were more common in men (vs women; p=0·041), patients aged 65 years or older (vs other age groups; p=0·048), patients with two or more comorbidities (vs one or none; p=0·0006), and patients with a history of smoking (vs no smoking history; p=0·0004). Sequelae were associated with hospitalisation for COVID-19 (p<0·0001), complicated COVID-19 (p<0·0001), and COVID-19 therapy (p=0·0002). With a median post-COVID-19 follow-up of 128 days (95% CI 113–148), COVID-19 sequelae were associated with an increased risk of death (hazard ratio [HR] 1·80 [95% CI 1·18–2·75]) after adjusting for time to post-COVID-19 reassessment, sex, age, comorbidity burden, tumour characteristics, anticancer therapy, and COVID-19 severity. Among 466 patients on systemic anti-cancer therapy, 70 (15·0%) permanently discontinued therapy, and 178 (38·2%) resumed treatment with a dose or regimen adjustment. Permanent treatment discontinuations were independently associated with an increased risk of death (HR 3·53 [95% CI 1·45–8·59]), but dose or regimen adjustments were not (0·84 [0·35–2·02]). Interpretation: Sequelae post-COVID-19 affect up to 15% of patients with cancer and adversely affect survival and oncological outcomes after recovery. Adjustments to systemic anti-cancer therapy can be safely pursued in treatment-eligible patients. Funding: National Institute for Health Research Imperial Biomedical Research Centre and the Cancer Treatment and Research Trust

    Systemic pro-inflammatory response identifies patients with cancer with adverse outcomes from SARS-CoV-2 infection: the OnCovid Inflammatory Score

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    Background: Cancer patients are particularly susceptible to SARS-CoV-2 infection. The systemic inflammatory response is a pathogenic mechanism shared by cancer progression and Covid-19. We investigated systemic inflammation as a driver of severity and mortality from Covid-19, evaluating the prognostic role of commonly utilized inflammatory indices in SARS-CoV-2-infected cancer patients accrued to the OnCovid study. Methods: In a multi-center cohort of SARS-CoV-2-infected cancer patients in Europe, we evaluated dynamic changes in neutrophil-lymphocyte ratio (NLR); platelet-lymphocyte ratio (PLR); prognostic nutritional index (PNI), renamed the OnCovid Inflammatory Score (OIS); modified Glasgow prognostic score (mGPS); and prognostic index (PI) in relationship to oncological and Covid-19 infection features, testing their prognostic potential in independent training (n=529) and validation (n=542) sets. Results: We evaluated 1,071 eligible patients: 625 (58.3%) males, 420 with malignancy in advanced stage (39.2%), most commonly genitourinary (n=216, 20.2%). 844 (78.8%) had ≥1 comorbidity and 754 (70.4%) ≥1 Covid-19 complication. NLR, OIS, and mGPS worsened at Covid-19 diagnosis compared to pre-Covid-19 measurement (P<0.01), recovering in survivors to pre-Covid-19 levels. Patients in poorer risk categories for each index except the PLR exhibited higher mortality rates (P<0.001) and shorter median overall survival in the training and validation sets (P<0.01). Multivariable analyses revealed the OIS to be most independently predictive of survival (validation set HR 2.48, 95% CI 1.47 – 4.20, P=0.001; adjusted C-index 0.611). Conclusions: Systemic inflammation is a validated prognostic domain in SARS-CoV-2-infected cancer patients and can be utilized as a bedside predictor of adverse outcome. Lymphocytopenia and hypoalbuminemia as computed by the OIS are independently predictive of severe Covid-19, supporting their use for risk stratification. Reversal of the Covid-19-induced pro-inflammatory state is a putative therapeutic strategy in patients with cancer
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