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First Dark Matter Search with Nuclear Recoils from the XENONnT Experiment. PHYSICAL REVIEW LETTERS 2023; 131:041003. [PMID: 37566859 DOI: 10.1103/physrevlett.131.041003] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/22/2023] [Indexed: 08/13/2023]
Abstract
We report on the first search for nuclear recoils from dark matter in the form of weakly interacting massive particles (WIMPs) with the XENONnT experiment, which is based on a two-phase time projection chamber with a sensitive liquid xenon mass of 5.9 ton. During the (1.09±0.03) ton yr exposure used for this search, the intrinsic ^{85}Kr and ^{222}Rn concentrations in the liquid target are reduced to unprecedentedly low levels, giving an electronic recoil background rate of (15.8±1.3) events/ton yr keV in the region of interest. A blind analysis of nuclear recoil events with energies between 3.3 and 60.5 keV finds no significant excess. This leads to a minimum upper limit on the spin-independent WIMP-nucleon cross section of 2.58×10^{-47} cm^{2} for a WIMP mass of 28 GeV/c^{2} at 90% confidence level. Limits for spin-dependent interactions are also provided. Both the limit and the sensitivity for the full range of WIMP masses analyzed here improve on previous results obtained with the XENON1T experiment for the same exposure.
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Searching for Heavy Dark Matter near the Planck Mass with XENON1T. PHYSICAL REVIEW LETTERS 2023; 130:261002. [PMID: 37450817 DOI: 10.1103/physrevlett.130.261002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/07/2023] [Accepted: 06/07/2023] [Indexed: 07/18/2023]
Abstract
Multiple viable theoretical models predict heavy dark matter particles with a mass close to the Planck mass, a range relatively unexplored by current experimental measurements. We use 219.4 days of data collected with the XENON1T experiment to conduct a blind search for signals from multiply interacting massive particles (MIMPs). Their unique track signature allows a targeted analysis with only 0.05 expected background events from muons. Following unblinding, we observe no signal candidate events. This Letter places strong constraints on spin-independent interactions of dark matter particles with a mass between 1×10^{12} and 2×10^{17} GeV/c^{2}. In addition, we present the first exclusion limits on spin-dependent MIMP-neutron and MIMP-proton cross sections for dark matter particles with masses close to the Planck scale.
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Contrasting adaptive genetic consequences of stream insects under changing climate. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 872:162258. [PMID: 36801338 DOI: 10.1016/j.scitotenv.2023.162258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 02/10/2023] [Accepted: 02/11/2023] [Indexed: 06/18/2023]
Abstract
Freshwater biodiversity undergoes degradation due to climate change. Researchers have inferred the effects of climate change on neutral genetic diversity, assuming the fixed spatial distributions of alleles. However, the adaptive genetic evolution of populations that may change the spatial distribution of allele frequencies along environmental gradients (i.e., evolutionary rescue) have largely been overlooked. We developed a modeling approach that projects the comparatively adaptive and neutral genetic diversities of four stream insects, using empirical neutral/ putative adaptive loci, ecological niche models (ENMs), and a distributed hydrological-thermal simulation at a temperate catchment under climate change. The hydrothermal model was used to generate hydraulic and thermal variables (e.g., annual current velocity and water temperature) at the present and the climatic change conditions, projected based on the eight general circulation models and the three representative concentration pathways scenarios for the two future periods (2031-2050, near future; 2081-2100, far future). The hydraulic and thermal variables were used for predictor variables of the ENMs and adaptive genetic modeling based on machine learning approaches. The increases in annual water temperature in the near- (+0.3-0.7 °C) and far-future (+0.4-3.2 °C) were projected. Of the studied species, with different ecologies and habitat ranges, Ephemera japonica (Ephemeroptera) was projected to lose rear-edge habitats (i.e., downstream) but retain the adaptive genetic diversity owing to evolutionary rescue. In contrast, the habitat range of the upstream-dwelling Hydropsyche albicephala (Trichoptera) was found to remarkably decline, resulting in decreases in the watershed genetic diversity. While the other two Trichoptera species expanded their habitat ranges, the genetic structures were homogenized over the watershed and experienced moderate decreases in gamma diversity. The findings emphasize the evolutionary rescue potential, depending on the extent of species-specific local adaptation.
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Search for New Physics in Electronic Recoil Data from XENONnT. PHYSICAL REVIEW LETTERS 2022; 129:161805. [PMID: 36306777 DOI: 10.1103/physrevlett.129.161805] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
We report on a blinded analysis of low-energy electronic recoil data from the first science run of the XENONnT dark matter experiment. Novel subsystems and the increased 5.9 ton liquid xenon target reduced the background in the (1, 30) keV search region to (15.8±1.3) events/(ton×year×keV), the lowest ever achieved in a dark matter detector and ∼5 times lower than in XENON1T. With an exposure of 1.16 ton-years, we observe no excess above background and set stringent new limits on solar axions, an enhanced neutrino magnetic moment, and bosonic dark matter.
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Material radiopurity control in the XENONnT experiment. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2022; 82:599. [PMID: 35821975 PMCID: PMC9270421 DOI: 10.1140/epjc/s10052-022-10345-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 04/19/2022] [Indexed: 11/18/2022]
Abstract
The selection of low-radioactive construction materials is of the utmost importance for rare-event searches and thus critical to the XENONnT experiment. Results of an extensive radioassay program are reported, in which material samples have been screened with gamma-ray spectroscopy, mass spectrometry, and \documentclass[12pt]{minimal}
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\begin{document}$$^{222}$$\end{document}222Rn emanation measurements. Furthermore, the cleanliness procedures applied to remove or mitigate surface contamination of detector materials are described. Screening results, used as inputs for a XENONnT Monte Carlo simulation, predict a reduction of materials background (\documentclass[12pt]{minimal}
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\begin{document}$$\sim $$\end{document}∼17%) with respect to its predecessor XENON1T. Through radon emanation measurements, the expected \documentclass[12pt]{minimal}
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\begin{document}$$^{222}$$\end{document}222Rn activity concentration in XENONnT is determined to be 4.2 (\documentclass[12pt]{minimal}
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\begin{document}$$^{+0.5}_{-0.7}$$\end{document}-0.7+0.5) \documentclass[12pt]{minimal}
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\begin{document}$$\upmu $$\end{document}μBq/kg, a factor three lower with respect to XENON1T. This radon concentration will be further suppressed by means of the novel radon distillation system.
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Clinical value of the HATCH score for predicting adverse outcomes in patients with heart failure. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehab849.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: None.
Background
The HATCH score is employed as a risk assessment tool for atrial fibrillation (AF) development. However, the impact of the HATCH score on the long-term adverse outcomes in patients with acute heart failure (AHF) is unknown.
Aimes
To investigate the clinical value of the HATCH score in AHF.
Methods
From a multicenter AHF registry, we retrospectively evaluated 1,543 consecutive patients admitted with AHF (median age, 78 [69–85] years; 42.3% women) from 2012 to 2019. These patients were divided into five groups based on their HATCH score at admission (scores 0, 1, 2, 3, and 4–7). The correlation between the HATCH score and composite outcome, including all-cause mortality and re-hospitalization due to HF, was analyzed using Kaplan-Meier and Cox proportional-hazard analyses.
Results
The median HATCH score was 2 [1-3]. During the follow-up period (median, 16.8 months), the composite endpoint occurred in 691 patients (44.8%), including 416 (27%) patients who died and 455 (29.5%) patients requiring re-hospitalizations due to HF. The Kaplan-Meier analysis showed a significant increase in the composite endpoint with increasing HATCH score (log-rank, p < 0.001). The multivariate Cox regression model revealed that the HATCH score was an independent predictor of the composite endpoint (hazard ratio [HR] 1.181; 95% confidence interval [CI]: 1.111–1.255; p < 0.001) with all-cause mortality (HR 1.153, 95% CI: 1.065–1.249; p < 0.001) and re-hospitalizations due to HF (HR 1.21; 95% CI: 1.124–1.303; p < 0.001) in patients with AHF.
Conclusions
The HATCH score is an independent predictor of adverse outcomes in patients with AHF. Abstract Figure. Kaplan-Meier analysis for outcome
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Serum autotaxin level predicts future cardiac events in patients with dilated cardiomyopathy. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.1730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Autotaxin (ATX) has been reported to promote myocardial inflammation and subsequent cardiac remodeling through lysophosphatidic acid (LPA) production. However, the prognostic impact of ATX has not been clarified in dilated cardiomyopathy (DCM).
Purpose
We aimed to investigate the prognostic impact of ATX in patients with DCM.
Methods
We enrolled 104 DCM patients (49.8 years, 76 males). The subjects underwent blood sampling, echocardiography, cardiac catheterization, and endomyocardial biopsy. Gender differences in serum ATX levels have been reported, thus we divided the subjects into two groups using median serum ATX levels for men and women: High-ATX group and Low-ATX group. All patients were followed up by expert cardiologists. The cardiac event was defined as a composite of cardiac death and hospitalization for worsening heart failure.
Results
Eighty-nine percent of the subjects were classified as New York Heart Association functional class I or II. Female patients had higher serum ATX levels than male patients, with median values of 257.0 ng/mL and 203.5 ng/mL, respectively (Figure A). The average left ventricular ejection fraction and brain natriuretic peptide levels were 30.6% and 122.5 pg/mL. In survival analysis, cumulative event-free probability was significantly lower in High ATX group (p=0.007, Figure B). In Cox proportional hazards analysis, High-ATX was one of the independent predictors of composite cardiac events (Hazards Ratio, 2.575; p=0.043). On the other hand, high sensitive C-reactive protein and collagen volume fraction in myocardial samples were not significant predictors.
Conclusion
High serum ATX level was associated with poor prognosis in patients with DCM.
Funding Acknowledgement
Type of funding sources: None. Gender difference in autotaxin levelsSurvival analysis of cardiac events
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Clinical significance of spleen size in patients with heart failure. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.0756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
The spleen is an important organ that stores blood, releases erythrocytes or monocytes, and destroys no-longer-needed platelets. It can reserve 20–30% of the total blood volume, and its size is reduced in hypovolemic shock. However, the clinical significance of the spleen size in patients with heart failure (HF) remains unclear.
Purpose
The purpose of this study was to investigate the relationship between spleen size, hemodynamic parameters, and prognosis in patients with HF.
Methods
A total of 219 patients with clinically stable HF were enrolled. All patients underwent right heart catheterisation and computed tomography. The spleen size was measured using computed tomography volumetry. In addition, spleen volume was assessed using the spleen volume index (SVI), corrected for body surface area. Cardiac events were composite endpoints of cardiac death, hospitalisation for worsening HF, fatal arrhythmias, implantation of cardiac devices, implantation of left ventricular assist devices, and unexpected percutaneous coronary intervention or cardiac surgery. Spearman's rank correlation coefficient was used to examine the relationship between spleen volume and hemodynamic parameters. Multivariate Cox hazard regression models were used to investigate whether SVI was an independent determinant of cardiac events.
Results
Of the 219 patients (median age, 54 [interquartile range] 46–64 years), 145 (66%) were males. The median (interquartile range) spleen volume and SVI was 118.0 (91.5–156.0) mL and 67.8 (54.9–87.2) mL/m2, respectively. SVI was positively correlated with cardiac output (r=0.269, P<0.001), and negatively correlated with systemic vascular resistance (r=−0.302, P<0.001) (Figure 1). A total of 70 cardiac events were observed, and the optimal cut-off value of SVI for cardiac events was 68.9 mL/m2 in the receiver operating characteristic analysis. Patients were divided into two groups: low-SVI (n=107, <68.9 mL/m2) and high-SVI groups (n=112, ≥68.9 mL/m2). Blood adrenaline concentration was higher in the low-SVI group than in the high-SVI group (0.039 [0.020–0.057] ng/mL vs 0.026 [0.014–0.044] ng/mL, P=0.004). The low-SVI group had more cardiac events than the high-SVI group (log-rank test, P<0.001) (Figure 2). In the multivariate Cox proportional hazard model, the low-SVI group was an independent predictor of cardiac events, even when adjusted for the conventional validated HF risk score, blood catecholamine levels, and hemodynamic parameters.
Conclusion
The spleen size may affect the prognosis in patients with HF, reflecting haemodynamics, including systemic circulating blood volume status and sympathetic nerve activity.
Funding Acknowledgement
Type of funding sources: None. Figure 1Figure 2
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Clinical impact of pulmonary artery to aorta diameter ratio on left ventricular reverse remodeling in patients with dilated cardiomyopathy. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.0757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Left ventricular reverse remodeling (LVRR) is an important predictor for a good prognosis in patients with dilated cardiomyopathy (DCM). Previous reports indicated the pulmonary artery diameter (PAD) to ascending aortic diameter (AoD) ratio as a predictor of adverse outcomes in heart failure patients. However, the impact of the PAD/AoD ratio for predicting LVRR in patients with DCM is unknown.
Aim
The aim of this study is to investigate the association between PAD/AoD ratio and LVRR in patients with DCM.
Methods
From a prospective study, clinically stable DCM patients who were investigated the LVRR on echocardiography and underwent CT at baseline were enrolled. LVRR is defined as left ventricular (LV) ejection fraction increase of 10% and a decrease in indexed LV end-diastolic diameter of 10% compared to those at baseline. PAD and AoD data was collected with nonenhanced computed tomography images at baseline.
Results
In sixty-nine patients (mean age 50.0±13.3 years), the mean LV ejection fraction was 29.8%, and mean LV end-diastolic dimension was 64.5mm, and both of which data was no significant difference between patients with or without LVRR. LVRR was observed in 23 (33.3%) patients. The PAD/AoD ratio was significantly lower in patients with LVRR than without LVRR (81.4% vs. 92.4%, p=0.003). By ROC analysis, the best cut-off for the detection of LVRR was found for a PAD/AoD ratio of 0.9. From multivariate analyses, PAD/AoD ratio was identified as a significant predictor of LVRR. After a median follow-up duration of 2.5 years, the DCM patients with PAD/AoD≥0.9 revealed a significant higher cardiac event than those with PAD/AoD<0.9 (log-rank, p=0.007)
Conclusions
The PAD/AoD ratio is useful for predicting LVRR in patients with DCM. The DCM patients with high PAD/AoD ratio had a poor long-term outcome.
Funding Acknowledgement
Type of funding sources: None. ROC curve for LVRR predictionKaplan-Meier survival curves
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222 Rn emanation measurements for the XENON1T experiment. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2021; 81:337. [PMID: 34720714 PMCID: PMC8550029 DOI: 10.1140/epjc/s10052-020-08777-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 12/17/2020] [Indexed: 06/13/2023]
Abstract
The selection of low-radioactive construction materials is of utmost importance for the success of low-energy rare event search experiments. Besides radioactive contaminants in the bulk, the emanation of radioactive radon atoms from material surfaces attains increasing relevance in the effort to further reduce the background of such experiments. In this work, we present the 222 Rn emanation measurements performed for the XENON1T dark matter experiment. Together with the bulk impurity screening campaign, the results enabled us to select the radio-purest construction materials, targeting a 222 Rn activity concentration of 10 μ Bq / kg in 3.2 t of xenon. The knowledge of the distribution of the 222 Rn sources allowed us to selectively eliminate problematic components in the course of the experiment. The predictions from the emanation measurements were compared to data of the 222 Rn activity concentration in XENON1T. The final 222 Rn activity concentration of ( 4.5 ± 0.1 ) μ Bq / kg in the target of XENON1T is the lowest ever achieved in a xenon dark matter experiment.
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Search for Coherent Elastic Scattering of Solar ^{8}B Neutrinos in the XENON1T Dark Matter Experiment. PHYSICAL REVIEW LETTERS 2021; 126:091301. [PMID: 33750173 DOI: 10.1103/physrevlett.126.091301] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/17/2021] [Accepted: 01/27/2021] [Indexed: 06/12/2023]
Abstract
We report on a search for nuclear recoil signals from solar ^{8}B neutrinos elastically scattering off xenon nuclei in XENON1T data, lowering the energy threshold from 2.6 to 1.6 keV. We develop a variety of novel techniques to limit the resulting increase in backgrounds near the threshold. No significant ^{8}B neutrinolike excess is found in an exposure of 0.6 t×y. For the first time, we use the nondetection of solar neutrinos to constrain the light yield from 1-2 keV nuclear recoils in liquid xenon, as well as nonstandard neutrino-quark interactions. Finally, we improve upon world-leading constraints on dark matter-nucleus interactions for dark matter masses between 3 and 11 GeV c^{-2} by as much as an order of magnitude.
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The prognostic impact of right ventricular dysfunction in patients with septic cardiomyopathy. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.1836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Sepsis is a systemic condition of profoundly impaired health in which an infection leads to a dysregulated host response, and consecutively causes organ dysfunction, shock, and even death. Septic cardiomyopathy (SCM) is one of the multiple organ dysfunctions. SCM is typically defined as left ventricular (LV) dysfunction, presented by decreased LV ejection fraction (LVEF). However, it remains unclear about the detailed mechanism of cardiac dysfunction. In addition, the prognostic impact of right heart dysfunction in SCM patients has not been fully investigated.
Purpose
The purpose of this study was to investigate the prognostic impact of right heart dysfunction in patients with SCM.
Methods
We used the MIMIC-III (Medical Information Mart for Intensive Care III) critical care database, which is a large, freely-available database comprising deidentified health-related data associated with over forty thousand patients who stayed in critical care units of the Beth Israel Deaconess Medical Center between 2001 and 2012. We retrospectively analyzed data of patients with septic shock on admission to intensive care unit (ICU). Septic shock was defined as the presence of any suspected infections, the need for vasopressors, and the lactate level exceeding 2 mmol/L, based on the Sepsis-3 criteria. Patients were performed portable transthoracic echocardiography (TTE) during hospitalization. LVEF and right ventricular (RV) function were determined predominately by visual estimation in the parasternal long-axis view. SCM was defined as having a minimum LVEF of 50% or less during hospitalization. Patients with hyperdynamic motion of LVEF >70% were excluded.
Results
In total, there were 2254 patients with septic shock. Of these, 604 patients who underwent TTE were enrolled, and 314 patients were diagnosed with SCM. At baseline, age, gender, Sequential Organ Failure Assessment (SOFA) score, maximum lactate levels, and maximum norepinephrine dosage were 70 [59–79] years, 194 males, 13 [11–15], 4.0 [2.7–6.2] mmol/L, and 0.20 [0.10–0.31] mcg/kg/min, respectively. All patients were treated with vasopressors. In Kaplan-Meier survival analysis, patients with SCM had increased 28-day mortality compared with those without SCM (log-rank, p=0.09). In addition, we divided SCM patients into two groups; SCM with and without RV dysfunction. SCM patients with RV dysfunction had significant increased 28-day mortality compared with those without RV dysfunction (log-rank, p=0.01) (Figure). In Cox proportional hazard regression analysis adjusted for age, male sex, SOFA score, and maximum lactate levels, RV dysfunction was an independent determinant of 28-day mortality (hazard ratio, 1.59; 95% confidence interval, 1.03–2.46; p=0.03).
Conclusions
The presence of RV dysfunction increased 28-day mortality in patients with SCM. It might be useful for predicting the prognosis of SCM to evaluate not only left heart function but also right heart function.
Kaplan-Meier survival curves
Funding Acknowledgement
Type of funding source: None
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Associations between spleen volume and exercise capacity in advanced heart failure patients with left ventricular assist device. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.1094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
The spleen has been recognized as an important organ with several functions such as a reservoir of blood volume, and an involvement in iron metabolism by processing of aged red blood cells and recycling iron. During exercise, spleen contracts, and red blood cells pooled in the spleen are recruited into the systemic circulation. So far, we reported that spleen size changed in advanced heart failure (HF) with left ventricular assist device (LVAD). In addition, spleen volume was related to pulmonary capillary wedge pressure (PCWP) or right atrial pressure (RAP) as parameters of cardiac preload. However, it remains unclear about the relationship between spleen volume and exercise capacity in advanced HF with LVAD.
Purpose
The purpose of this study was to investigate the associations between spleen volume and exercise capacity in advanced HF patients with LVAD.
Methods
We enrolled 27 HF patients (21 males, 45±12 years) with LVAD (HeartMate II™; Abbott, Chicago, IL, USA) for use as a bridge to heart transplantation. All patients underwent blood test, echocardiography, right heart catheterization, computed tomography (CT) and cardiopulmonary exercise testing (CPET). Spleen size was measured by CT volumetry. We excluded patients with splenic infarction or aortic valve closure surgery.
Results
At baseline, body mass index, blood brain natriuretic peptide levels, hemoglobin levels, left ventricular ejection fraction were 21.4±3.1 kg/m2, 73.8 (51.9–165.8) pg/mL, 12.1 (10.6–13.4) g/dL, 24.8±14.7%, respectively. Total cardiac output (CO), the sum of pump flow and CO of native heart was 4.6±0.9 L/min, and spleen volume was 184.9±48.8 mL. As for parameters of CPET, peak heart rate (HR), peak VO2, and peak O2 pulse were 128±25 beats/min, 14.2±3.3 mL/kg/min, and 6.6±1.9 mL/beat. At rest, there were significant correlations between spleen volume and PCWP (r=0.382, p=0.049), RAP (r=0.406, p=0.035) or pulsatility index (r=0.384, p=0.047), despite no correlations with total CO or pump flow. During exercise, there were significant interrelations of spleen volume with peak VO2 (r=0.451, p=0.018) and peak O2 pulse (r=0.427, p=0.026). Furthermore, peak VO2 was interrelated with peak HR (r=0.481, p=0.011) or hemoglobin levels (r=0.649, p<0.001). Remarkably, spleen volume was significantly correlated with hemoglobin levels (r=0.391, p=0.043) (Figure). Interpreting these results based on Fick's formula, the proportion of native CO to total CO is very small at rest, but increases during exercise. The spleen during exercise may contribute to increased native CO, especially stroke volume. Moreover, the spleen may be related to both cardiac preload and oxygen carrying capacity, resulting in a significant association between spleen volume and peak VO2.
Conclusion
Spleen volume could be a useful predictor of exercise capacity in advanced HF patients with LVAD, reflecting splenic function to modulate cardiac preload and blood hemoglobin levels.
Spleen volume and exercise parameters
Funding Acknowledgement
Type of funding source: None
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Efficacy of right ventricular dysfunction estimated by pulmonary artery pulsatility index in stable phased dilated cardiomyopathy. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.0902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Dilated cardiomyopathy (DCM) is characterized by a reduction in left and/or right ventricular myocardial contraction, dilatation of biventricular cavity and major cause of heart failure with high morbidity and mortality rates. Right ventricular dysfunction (RVD) recently have been received attention because of 34% of DCM had RVD and considered as a powerful predictor of impaired prognosis in DCM. Pulmonary Artery Pulsatility index (PAPi) is a novel hemodynamic index shown to predict RVD in advanced heart failure, however, it is unknown that even at early phase, PAPi can reflects latent right myocardial damage and predict long-term prognosis in stable DCM patients.
Methods
From April 2000 to March 2018, we enrolled 566 consecutive patients with cardiomyopathy. All patients underwent laboratory measurement, echocardiography, and cardiac catheterization to evaluate their general conditions. After excluded secondary cardiomyopathy, ischemic cardiomyopathy, and valvular heart disease, finally 162 DCM patients were enrolled. All enrolled patients had NYHA I/II/III and NYHA I/II were 150 patients (92.6%). PAPi was calculated as (systolic pulmonary artery pressure – diastolic pulmonary artery pressure (Pulmonary artery pulse pressure: PAPP)) / right atrial pressure. Median followed up for 4.85 years. In this study 149 patients were performed endomyocardial biopsy in order to exclude secondary cardiomyopathies and 95 patients were assessed using Sirius red staining. Myocardial fibrosis in biopsy specimen was assessed using Sirius red staining, and the positive region was quantified as the collagen volume fraction (CVF).
Results
The mean age and LV ejection fraction (EF) was 50.9±12.6 years and 30.5±8.3%, respectively. When divided into two groups by median PAPi value [PAPi <3.06 (L-PAP) and PAPi ≥3.06 (H-PAP)], even though there were no significant difference in BNP, pulmonary vascular resistance and right ventricular stroke work index between two groups, the probability of cardiac event-survival was significantly higher in L-PAP than H-PAP by Kaplan-Meier analysis (P=0.012). Furthermore, cox proportional hazard regression analysis revealed that PAPi was independent predictor of cardiac events (hazard ratio: 0.624, P=0.025). In pathological analysis, there was no difference between H-PAPi and L-PAPi in CVF.
Conclusion
In the calculation of PAPi, PAPP reflects both RV contractility and left atrial filling pressure and this index considered as RV adaptive response to afterload. The denominator of the PAPP is defined by RA pressure, which serves as a marker of RV preload. Thus, PAPi reflect both preload and afterload of RV at the same time and even though estimated patients at early phase, RVD exists in DCM patients without severe myocardial fibrosis, and PAPi may help stratify DCM and predict cardiac events.
Kaplan-Meier analysis
Funding Acknowledgement
Type of funding source: None
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Abstract
Abstract
Background and purpose
Fluorine-18-flurodeoxyglucose positron emission tomography (18FDG-PET) is a useful examination assessing active inflammatory myocardium noninvasively in patients with cardiac sarcoidosis (CS). Though immunosuppression like prednisolone (PSL) and Methotrexate (MTX) as alternative therapy is used to suppress the inflammation, little is known about the rate of response and efficacy of MTX for intolerance to PSL therapy.
Methods
From Aug 2016, we prospectively enrolled CS with positively accumulated of FDG in the heart. The initial dose of PSL was 30mg/day, wherefrom the dose was tapered down 5mg/month until 6 months. After 6 months, follow-up 18FDG-PET was performed. Using 18FDG-PET images, we calculated total lesion glycolysis (TLG; SUVmeam x metabolic volume) and calculated the reduction rate of TLG. In order to estimate the response rate to PSL therapy, responder group (R-group) was defined as TLG reduction rate ≥70% and poor-responder group (PR-group) was defined as TLG reduction rate <70% after PSL therapy. After prescribed PSL, subjects with PR-group randomized to PSL (maximum dose 30mg daily and tapered down 5mg/month until 6 months) or to MTX (6mg weekly).
Results
In 64 CS patients, 55 patients had serial 18FDG-PET before and 6 months after PSL therapy. 18FDG-PET images were acquired following 7 day's carbohydrate limitation and after at least 18-h fasting (mean free fatty acid level right before 18FDG-PET acquisition was 1.05 mEq/L). The mean age was 63.4 years old and 42 (76.4%) patients were female. Because of 6 months PSL therapy, even though there were no significant difference in BNP (from 59.9 (26.2–137.6) to 60.4 (18.5–122.0) (P=0.593), LV-Dd (from 50.9 (44.5–59.5) to 49.7 (45.5–61.3) (P=0.666) and LV-EF (from 49.5 (34.4–62.5) to 49.9 (38.0–62.0) (P=0.792) at pre and post therapy, respectively, TLG were detected significant reduction from 216.4 (74.2–411.6) to 0.8 (0.0–8.2), (p<0.001). In response to PSL therapy, 47 (85.5%) CS patients were classified to R-group and 8 (14.5%) were classified to PR-group. Furthermore, when performed block randomization and divide 8 PR-group patients into MTX (n=3) and re-increased PSL (n=5) for more 6 months, MTX group is prone to high rate of TLG reduction than re-increased PSL-group (89.4% vs 59.9%) and one patient belonged to re-increased PSL group showed that the further elevation of TLG level at additional 6-months PSL therapy (349⇒483) (Figure).
Conclusions
1) By immunosuppression therapy using PSL for CS, about 86% patients showed significant reduction of myocardial FDG accumulation. 2) When detected intolerance for PSL therapy, MTX might be effective for reduction of inflammation of sarcoidosis in the heart, which might be effective as an alternate therapy in CS.
The TLG level after randomization
Funding Acknowledgement
Type of funding source: Public Institution(s). Main funding source(s): Grant-in-aid for scientific research
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A case of resected retroperitoneal metachronous solitary metastasis from caecal cancer. Ann R Coll Surg Engl 2020; 102:e198-e201. [PMID: 32538111 DOI: 10.1308/rcsann.2020.0107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Colorectal cancer metastasis to the retroperitoneum, especially solitary metastasis allowing curative resection, is rare. We report a case of complete resection of retroperitoneal metachronous solitary metastasis from caecal cancer without distant metastasis. An 80-year-old woman with caecal cancer underwent laparoscopic ileocaecal resection with regional lymph node dissection. According to the eighth edition of the TNM classification, the pathological diagnosis was stage IIA (T3N0M0). Six months following the surgery, computed tomography revealed a solitary mass of 2cm diameter, dorsal to the right kidney. A second procedure for the removal of the tumour was performed. The lesion was pathologically diagnosed as a metachronous solitary retroperitoneal metastasis from caecal cancer. The patient is surviving and free from recurrence 17 months following the second procedure.
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Aquatic insect community structure revealed by eDNA metabarcoding derives indices for environmental assessment. PeerJ 2020; 8:e9176. [PMID: 32566391 PMCID: PMC7293852 DOI: 10.7717/peerj.9176] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 04/21/2020] [Indexed: 12/25/2022] Open
Abstract
Environmental DNA (eDNA) analysis provides an efficient and objective approach for monitoring and assessing ecological status; however, studies on the eDNA of aquatic insects, such as Ephemeroptera, Plecoptera, and Trichoptera (EPT), are limited despite its potential as a useful indicator of river health. Here, we investigated the community structures of aquatic insects using eDNA and evaluated the applicability of eDNA data for calculating assessment indices. Field surveys were conducted to sample river water for eDNA at six locations from upstream to downstream of two rivers in Japan in July and November 2016. Simultaneously, aquatic insects were collected using the traditional Surber net survey method. The communities of aquatic insects were revealed using eDNA by targeting the cytochrome oxidase subunit I gene in mitochondrial DNA via metabarcoding analyses. As a result, the eDNA revealed 63 families and 75 genera of aquatic insects, which was double than that detected by the Surber net survey (especially for families in Diptera and Hemiptera). The seasonal differences of communities were distinguished by both the eDNA and Surber net survey data. Furthermore, the total nitrogen concentration, a surrogate of organic pollution, showed positive correlations with biotic environmental assessment indices (i.e., EPT index and Chironomidae index) calculated using eDNA at the genus-level resolution but the indices calculated using the Surber net survey data. Our results demonstrated that eDNA analysis with higher taxonomic resolution can provide as a more sensitive environmental assessment index than the traditional method that requires biotic samples.
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Light Dark Matter Search with Ionization Signals in XENON1T. PHYSICAL REVIEW LETTERS 2019; 123:251801. [PMID: 31922764 DOI: 10.1103/physrevlett.123.251801] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 11/07/2019] [Indexed: 06/10/2023]
Abstract
We report constraints on light dark matter (DM) models using ionization signals in the XENON1T experiment. We mitigate backgrounds with strong event selections, rather than requiring a scintillation signal, leaving an effective exposure of (22±3) tonne day. Above ∼0.4 keV_{ee}, we observe <1 event/(tonne day keV_{ee}), which is more than 1000 times lower than in similar searches with other detectors. Despite observing a higher rate at lower energies, no DM or CEvNS detection may be claimed because we cannot model all of our backgrounds. We thus exclude new regions in the parameter spaces for DM-nucleus scattering for DM masses m_{χ} within 3-6 GeV/c^{2}, DM-electron scattering for m_{χ}>30 MeV/c^{2}, and absorption of dark photons and axionlike particles for m_{χ} within 0.186-1 keV/c^{2}.
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Search for Light Dark Matter Interactions Enhanced by the Migdal Effect or Bremsstrahlung in XENON1T. PHYSICAL REVIEW LETTERS 2019; 123:241803. [PMID: 31922867 DOI: 10.1103/physrevlett.123.241803] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 10/15/2019] [Indexed: 06/10/2023]
Abstract
Direct dark matter detection experiments based on a liquid xenon target are leading the search for dark matter particles with masses above ∼5 GeV/c^{2}, but have limited sensitivity to lighter masses because of the small momentum transfer in dark matter-nucleus elastic scattering. However, there is an irreducible contribution from inelastic processes accompanying the elastic scattering, which leads to the excitation and ionization of the recoiling atom (the Migdal effect) or the emission of a bremsstrahlung photon. In this Letter, we report on a probe of low-mass dark matter with masses down to about 85 MeV/c^{2} by looking for electronic recoils induced by the Migdal effect and bremsstrahlung using data from the XENON1T experiment. Besides the approach of detecting both scintillation and ionization signals, we exploit an approach that uses ionization signals only, which allows for a lower detection threshold. This analysis significantly enhances the sensitivity of XENON1T to light dark matter previously beyond its reach.
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The effects of spatial discretization on performances and parameters of urban hydrological model. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2019; 80:517-528. [PMID: 31596263 DOI: 10.2166/wst.2019.296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Selecting a proper spatial resolution for urban rainfall runoff modeling was not a trivial issue because it could affect the model outputs. Recently, the development of remote sensing technology and increasingly available data source had enabled rainfall runoff process to be modeled at detailed and microscales. However, the models with less complexity might have equally good performance with less model establishment and computation time. This study attempted to explore the impact of model spatial resolution on model performance and parameters. Models with different discretization degree were built up on the basis of actual drainage networks, urban parcels and specific land use. The results showed that there was very little difference in the total runoff volumes while peak flows showed obvious scale effects which could be up to 30%. Generally, model calibration could compensate the scale effect. The calibrated models with different resolution showed similar performances. The consideration of effective impervious area (EIA) as a calibration parameter marginally increased performance of the calibration period but also slightly decreased performance in the validation period which indicated the importance of detailed EIA identification.
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Constraining the Spin-Dependent WIMP-Nucleon Cross Sections with XENON1T. PHYSICAL REVIEW LETTERS 2019; 122:141301. [PMID: 31050482 DOI: 10.1103/physrevlett.122.141301] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 03/07/2019] [Indexed: 06/09/2023]
Abstract
We report the first experimental results on spin-dependent elastic weakly interacting massive particle (WIMP) nucleon scattering from the XENON1T dark matter search experiment. The analysis uses the full ton year exposure of XENON1T to constrain the spin-dependent proton-only and neutron-only cases. No significant signal excess is observed, and a profile likelihood ratio analysis is used to set exclusion limits on the WIMP-nucleon interactions. This includes the most stringent constraint to date on the WIMP-neutron cross section, with a minimum of 6.3×10^{-42} cm^{2} at 30 GeV/c^{2} and 90% confidence level. The results are compared with those from collider searches and used to exclude new parameter space in an isoscalar theory with an axial-vector mediator.
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First Results on the Scalar WIMP-Pion Coupling, Using the XENON1T Experiment. PHYSICAL REVIEW LETTERS 2019; 122:071301. [PMID: 30848617 DOI: 10.1103/physrevlett.122.071301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Indexed: 06/09/2023]
Abstract
We present first results on the scalar coupling of weakly interacting massive particles (WIMPs) to pions from 1 t yr of exposure with the XENON1T experiment. This interaction is generated when the WIMP couples to a virtual pion exchanged between the nucleons in a nucleus. In contrast to most nonrelativistic operators, these pion-exchange currents can be coherently enhanced by the total number of nucleons and therefore may dominate in scenarios where spin-independent WIMP-nucleon interactions are suppressed. Moreover, for natural values of the couplings, they dominate over the spin-dependent channel due to their coherence in the nucleus. Using the signal model of this new WIMP-pion channel, no significant excess is found, leading to an upper limit cross section of 6.4×10^{-46} cm^{2} (90% confidence level) at 30 GeV/c^{2} WIMP mass.
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Projection of invertebrate populations in the headwater streams of a temperate catchment under a changing climate. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 642:610-618. [PMID: 29909328 DOI: 10.1016/j.scitotenv.2018.06.109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 06/09/2018] [Accepted: 06/09/2018] [Indexed: 06/08/2023]
Abstract
Climate change places considerable stress on riverine ecosystems by altering flow regimes and increasing water temperature. This study evaluated how water temperature increases under climate change scenarios will affect stream invertebrates in pristine headwater streams. The studied headwater-stream sites were distributed within a temperate catchment of Japan and had similar hydraulic-geographical conditions, but were subject to varying temperature conditions due to altitudinal differences (100 to 850 m). We adopted eight general circulation models (GCMs) to project air temperature under conservative (RCP2.6), intermediate (RCP4.5), and extreme climate scenarios (RCP8.5) during the near (2031-2050) and far (2081-2100) future. Using the water temperature of headwater streams computed by a distributed hydrological-thermal model as a predictor variable, we projected the population density of stream invertebrates in the future scenarios based on generalized linear models. The mean decrease in the temporally averaged population density of Plecoptera was 61.3% among the GCMs, even under RCP2.6 in the near future, whereas density deteriorated even further (90.7%) under RCP8.5 in the far future. Trichoptera density was also projected to greatly deteriorate under RCP8.5 in the far future. We defined taxa that exhibited temperature-sensitive declines under climate change as cold stenotherms and found that most Plecoptera taxa were cold stenotherms in comparison to other orders. Specifically, the taxonomic families that only distribute in Palearctic realm (e.g., Megarcys ochracea and Scopura longa) were selectively assigned, suggesting that Plecoptera family with its restricted distribution in the Palearctic might be a sensitive indicator of climate change. Plecoptera and Trichoptera populations in the headwaters are expected/anticipated to decrease over the considerable geographical range of the catchment, even under the RCP2.6 in the near future. Given headwater invertebrates play important roles in streams, such as contributing to watershed productivity, our results provide useful information for managing streams at the catchment-level.
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Dark Matter Search Results from a One Ton-Year Exposure of XENON1T. PHYSICAL REVIEW LETTERS 2018; 121:111302. [PMID: 30265108 DOI: 10.1103/physrevlett.121.111302] [Citation(s) in RCA: 177] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/14/2018] [Indexed: 06/08/2023]
Abstract
We report on a search for weakly interacting massive particles (WIMPs) using 278.8 days of data collected with the XENON1T experiment at LNGS. XENON1T utilizes a liquid xenon time projection chamber with a fiducial mass of (1.30±0.01) ton, resulting in a 1.0 ton yr exposure. The energy region of interest, [1.4,10.6] keV_{ee} ([4.9,40.9] keV_{nr}), exhibits an ultralow electron recoil background rate of [82_{-3}^{+5}(syst)±3(stat)] events/(ton yr keV_{ee}). No significant excess over background is found, and a profile likelihood analysis parametrized in spatial and energy dimensions excludes new parameter space for the WIMP-nucleon spin-independent elastic scatter cross section for WIMP masses above 6 GeV/c^{2}, with a minimum of 4.1×10^{-47} cm^{2} at 30 GeV/c^{2} and a 90% confidence level.
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P4485Haemodynamic and electrical safety of neuromuscular electrical stimulation in acute decompensated heart failure. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy563.p4485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Estimation of periphyton dynamics in a temperate catchment using a distributed nutrient-runoff model. Ecol Modell 2018. [DOI: 10.1016/j.ecolmodel.2017.11.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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First Dark Matter Search Results from the XENON1T Experiment. PHYSICAL REVIEW LETTERS 2017; 119:181301. [PMID: 29219593 DOI: 10.1103/physrevlett.119.181301] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Indexed: 06/07/2023]
Abstract
We report the first dark matter search results from XENON1T, a ∼2000-kg-target-mass dual-phase (liquid-gas) xenon time projection chamber in operation at the Laboratori Nazionali del Gran Sasso in Italy and the first ton-scale detector of this kind. The blinded search used 34.2 live days of data acquired between November 2016 and January 2017. Inside the (1042±12)-kg fiducial mass and in the [5,40] keV_{nr} energy range of interest for weakly interacting massive particle (WIMP) dark matter searches, the electronic recoil background was (1.93±0.25)×10^{-4} events/(kg×day×keV_{ee}), the lowest ever achieved in such a dark matter detector. A profile likelihood analysis shows that the data are consistent with the background-only hypothesis. We derive the most stringent exclusion limits on the spin-independent WIMP-nucleon interaction cross section for WIMP masses above 10 GeV/c^{2}, with a minimum of 7.7×10^{-47} cm^{2} for 35-GeV/c^{2} WIMPs at 90% C.L.
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Topological cell clustering in the ATLAS calorimeters and its performance in LHC Run 1. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2017; 77:490. [PMID: 28943797 PMCID: PMC5586976 DOI: 10.1140/epjc/s10052-017-5004-5] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 06/21/2017] [Indexed: 05/07/2023]
Abstract
The reconstruction of the signal from hadrons and jets emerging from the proton-proton collisions at the Large Hadron Collider (LHC) and entering the ATLAS calorimeters is based on a three-dimensional topological clustering of individual calorimeter cell signals. The cluster formation follows cell signal-significance patterns generated by electromagnetic and hadronic showers. In this, the clustering algorithm implicitly performs a topological noise suppression by removing cells with insignificant signals which are not in close proximity to cells with significant signals. The resulting topological cell clusters have shape and location information, which is exploited to apply a local energy calibration and corrections depending on the nature of the cluster. Topological cell clustering is established as a well-performing calorimeter signal definition for jet and missing transverse momentum reconstruction in ATLAS.
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Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton-proton collisions at the LHC. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2017; 77:332. [PMID: 28943786 PMCID: PMC5586242 DOI: 10.1140/epjc/s10052-017-4887-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 05/05/2017] [Indexed: 05/30/2023]
Abstract
This paper presents the method and performance of primary vertex reconstruction in proton-proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of [Formula: see text] TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about [Formula: see text] is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than [Formula: see text] and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing.
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Performance of algorithms that reconstruct missing transverse momentum in [Formula: see text]= 8 TeV proton-proton collisions in the ATLAS detector. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2017; 77:241. [PMID: 28515666 PMCID: PMC5409168 DOI: 10.1140/epjc/s10052-017-4780-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 03/21/2017] [Indexed: 05/23/2023]
Abstract
The reconstruction and calibration algorithms used to calculate missing transverse momentum ([Formula: see text] ) with the ATLAS detector exploit energy deposits in the calorimeter and tracks reconstructed in the inner detector as well as the muon spectrometer. Various strategies are used to suppress effects arising from additional proton-proton interactions, called pileup, concurrent with the hard-scatter processes. Tracking information is used to distinguish contributions from the pileup interactions using their vertex separation along the beam axis. The performance of the [Formula: see text] reconstruction algorithms, especially with respect to the amount of pileup, is evaluated using data collected in proton-proton collisions at a centre-of-mass energy of 8 [Formula: see text] during 2012, and results are shown for a data sample corresponding to an integrated luminosity of [Formula: see text]. The simulation and modelling of [Formula: see text] in events containing a Z boson decaying to two charged leptons (electrons or muons) or a W boson decaying to a charged lepton and a neutrino are compared to data. The acceptance for different event topologies, with and without high transverse momentum neutrinos, is shown for a range of threshold criteria for [Formula: see text] , and estimates of the systematic uncertainties in the [Formula: see text] measurements are presented.
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Search for lepton-flavour-violating decays of the Higgs and Z bosons with the ATLAS detector. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2017; 77:70. [PMID: 28775664 PMCID: PMC5512745 DOI: 10.1140/epjc/s10052-017-4624-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 01/15/2017] [Indexed: 06/06/2023]
Abstract
Direct searches for lepton flavour violation in decays of the Higgs and Z bosons with the ATLAS detector at the LHC are presented. The following three decays are considered: [Formula: see text], [Formula: see text], and [Formula: see text]. The searches are based on the data sample of proton-proton collisions collected by the ATLAS detector corresponding to an integrated luminosity of 20.3 [Formula: see text] at a centre-of-mass energy of [Formula: see text] TeV. No significant excess is observed, and upper limits on the lepton-flavour-violating branching ratios are set at the 95[Formula: see text] confidence level: Br[Formula: see text], Br[Formula: see text], and Br[Formula: see text].
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Measurement of the [Formula: see text] and [Formula: see text] production cross sections in multilepton final states using 3.2 fb[Formula: see text] of [Formula: see text] collisions at [Formula: see text] = 13 TeV with the ATLAS detector. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2017; 77:40. [PMID: 28260981 PMCID: PMC5312089 DOI: 10.1140/epjc/s10052-016-4574-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 12/13/2016] [Indexed: 06/06/2023]
Abstract
A measurement of the [Formula: see text] and [Formula: see text] production cross sections in final states with either two same-charge muons, or three or four leptons (electrons or muons) is presented. The analysis uses a data sample of proton-proton collisions at [Formula: see text] TeV recorded with the ATLAS detector at the Large Hadron Collider in 2015, corresponding to a total integrated luminosity of 3.2 fb[Formula: see text]. The inclusive cross sections are extracted using likelihood fits to signal and control regions, resulting in [Formula: see text] pb and [Formula: see text] pb, in agreement with the Standard Model predictions.
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Measurement of the [Formula: see text] dijet cross section in pp collisions at [Formula: see text] TeV with the ATLAS detector. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2016; 76:670. [PMID: 28316501 PMCID: PMC5335597 DOI: 10.1140/epjc/s10052-016-4521-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/17/2016] [Indexed: 05/30/2023]
Abstract
The dijet production cross section for jets containing a b-hadron (b-jets) has been measured in proton-proton collisions with a centre-of-mass energy of [Formula: see text] TeV, using the ATLAS detector at the LHC. The data used correspond to an integrated luminosity of [Formula: see text]. The cross section is measured for events with two identified b-jets with a transverse momentum [Formula: see text] GeV and a minimum separation in the [Formula: see text]-[Formula: see text] plane of [Formula: see text]. At least one of the jets in the event is required to have [Formula: see text] GeV. The cross section is measured differentially as a function of dijet invariant mass, dijet transverse momentum, boost of the dijet system, and the rapidity difference, azimuthal angle and angular distance between the b-jets. The results are compared to different predictions of leading order and next-to-leading order perturbative quantum chromodynamics matrix elements supplemented with models for parton-showers and hadronization.
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Measurement of the photon identification efficiencies with the ATLAS detector using LHC Run-1 data. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2016; 76:666. [PMID: 28316500 PMCID: PMC5335650 DOI: 10.1140/epjc/s10052-016-4507-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 11/14/2016] [Indexed: 05/23/2023]
Abstract
The algorithms used by the ATLAS Collaboration to reconstruct and identify prompt photons are described. Measurements of the photon identification efficiencies are reported, using 4.9 fb[Formula: see text] of pp collision data collected at the LHC at [Formula: see text] [Formula: see text] and 20.3 fb[Formula: see text] at [Formula: see text] [Formula: see text]. The efficiencies are measured separately for converted and unconverted photons, in four different pseudorapidity regions, for transverse momenta between 10 [Formula: see text] and 1.5 [Formula: see text]. The results from the combination of three data-driven techniques are compared to the predictions from a simulation of the detector response, after correcting the electromagnetic shower momenta in the simulation for the average differences observed with respect to data. Data-to-simulation efficiency ratios used as correction factors in physics measurements are determined to account for the small residual efficiency differences. These factors are measured with uncertainties between 0.5% and 10% in 7 [Formula: see text] data and between 0.5% and 5.6% in 8 [Formula: see text] data, depending on the photon transverse momentum and pseudorapidity.
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Test of CP invariance in vector-boson fusion production of the Higgs boson using the Optimal Observable method in the ditau decay channel with the ATLAS detector. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2016; 76:658. [PMID: 28316497 PMCID: PMC5335599 DOI: 10.1140/epjc/s10052-016-4499-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 11/08/2016] [Indexed: 06/06/2023]
Abstract
A test of CP invariance in Higgs boson production via vector-boson fusion using the method of the Optimal Observable is presented. The analysis exploits the decay mode of the Higgs boson into a pair of [Formula: see text] leptons and is based on 20.3 [Formula: see text] of proton-proton collision data at [Formula: see text] = 8 [Formula: see text] collected by the ATLAS experiment at the LHC. Contributions from CP-violating interactions between the Higgs boson and electroweak gauge bosons are described in an effective field theory framework, in which the strength of CP violation is governed by a single parameter [Formula: see text]. The mean values and distributions of CP-odd observables agree with the expectation in the Standard Model and show no sign of CP violation. The CP-mixing parameter [Formula: see text] is constrained to the interval [Formula: see text] at 68% confidence level, consistent with the Standard Model expectation of [Formula: see text].
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Performance of pile-up mitigation techniques for jets in [Formula: see text] collisions at [Formula: see text] TeV using the ATLAS detector. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2016; 76:581. [PMID: 28316490 PMCID: PMC5335592 DOI: 10.1140/epjc/s10052-016-4395-z] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 09/26/2016] [Indexed: 05/07/2023]
Abstract
The large rate of multiple simultaneous proton-proton interactions, or pile-up, generated by the Large Hadron Collider in Run 1 required the development of many new techniques to mitigate the adverse effects of these conditions. This paper describes the methods employed in the ATLAS experiment to correct for the impact of pile-up on jet energy and jet shapes, and for the presence of spurious additional jets, with a primary focus on the large 20.3 [Formula: see text] data sample collected at a centre-of-mass energy of [Formula: see text]. The energy correction techniques that incorporate sophisticated estimates of the average pile-up energy density and tracking information are presented. Jet-to-vertex association techniques are discussed and projections of performance for the future are considered. Lastly, the extension of these techniques to mitigate the effect of pile-up on jet shapes using subtraction and grooming procedures is presented.
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Search for gluinos in events with an isolated lepton, jets and missing transverse momentum at [Formula: see text] = 13 Te V with the ATLAS detector. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2016; 76:565. [PMID: 28316489 PMCID: PMC5335548 DOI: 10.1140/epjc/s10052-016-4397-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 09/26/2016] [Indexed: 06/06/2023]
Abstract
The results of a search for gluinos in final states with an isolated electron or muon, multiple jets and large missing transverse momentum using proton-proton collision data at a centre-of-mass energy of [Formula: see text] are presented. The dataset used was recorded in 2015 by the ATLAS experiment at the Large Hadron Collider and corresponds to an integrated luminosity of 3.2 fb[Formula: see text]. Six signal selections are defined that best exploit the signal characteristics. The data agree with the Standard Model background expectation in all six signal selections, and the largest deviation is a 2.1 standard deviation excess. The results are interpreted in a simplified model where pair-produced gluinos decay via the lightest chargino to the lightest neutralino. In this model, gluinos are excluded up to masses of approximately 1.6 Te V depending on the mass spectrum of the simplified model, thus surpassing the limits of previous searches.
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The performance of the jet trigger for the ATLAS detector during 2011 data taking. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2016; 76:526. [PMID: 28316483 PMCID: PMC5335543 DOI: 10.1140/epjc/s10052-016-4325-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 08/18/2016] [Indexed: 05/23/2023]
Abstract
The performance of the jet trigger for the ATLAS detector at the LHC during the 2011 data taking period is described. During 2011 the LHC provided proton-proton collisions with a centre-of-mass energy of 7 TeV and heavy ion collisions with a 2.76 TeV per nucleon-nucleon collision energy. The ATLAS trigger is a three level system designed to reduce the rate of events from the 40 MHz nominal maximum bunch crossing rate to the approximate 400 Hz which can be written to offline storage. The ATLAS jet trigger is the primary means for the online selection of events containing jets. Events are accepted by the trigger if they contain one or more jets above some transverse energy threshold. During 2011 data taking the jet trigger was fully efficient for jets with transverse energy above 25 GeV for triggers seeded randomly at Level 1. For triggers which require a jet to be identified at each of the three trigger levels, full efficiency is reached for offline jets with transverse energy above 60 GeV. Jets reconstructed in the final trigger level and corresponding to offline jets with transverse energy greater than 60 GeV, are reconstructed with a resolution in transverse energy with respect to offline jets, of better than 4 % in the central region and better than 2.5 % in the forward direction.
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Study of the rare decays of [Formula: see text] and [Formula: see text] into muon pairs from data collected during the LHC Run 1 with the ATLAS detector. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2016; 76:513. [PMID: 28775663 PMCID: PMC5512627 DOI: 10.1140/epjc/s10052-016-4338-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 08/25/2016] [Indexed: 06/06/2023]
Abstract
A study of the decays [Formula: see text] and [Formula: see text] has been performed using data corresponding to an integrated luminosity of 25 fb[Formula: see text] of 7 and 8 TeV proton-proton collisions collected with the ATLAS detector during the LHC Run 1. For the [Formula: see text] dimuon decay, an upper limit on the branching fraction is set at [Formula: see text] at 95 % confidence level. For [Formula: see text], the branching fraction [Formula: see text] is measured. The results are consistent with the Standard Model expectation with a p value of 4.8 %, corresponding to 2.0 standard deviations.
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Charged-particle distributions at low transverse momentum in [Formula: see text] TeV pp interactions measured with the ATLAS detector at the LHC. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2016; 76:502. [PMID: 28316503 PMCID: PMC5335502 DOI: 10.1140/epjc/s10052-016-4335-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 08/23/2016] [Indexed: 05/10/2023]
Abstract
Measurements of distributions of charged particles produced in proton-proton collisions with a centre-of-mass energy of 13 TeV are presented. The data were recorded by the ATLAS detector at the LHC and correspond to an integrated luminosity of 151 [Formula: see text]. The particles are required to have a transverse momentum greater than 100 MeV and an absolute pseudorapidity less than 2.5. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity and the dependence of the mean transverse momentum on multiplicity are measured in events containing at least two charged particles satisfying the above kinematic criteria. The results are corrected for detector effects and compared to the predictions from several Monte Carlo event generators.
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Search for new phenomena in final states with an energetic jet and large missing transverse momentum in ppcollisions at s=13 TeVusing the ATLAS detector. Int J Clin Exp Med 2016. [DOI: 10.1103/physrevd.94.032005] [Citation(s) in RCA: 130] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Search for pair production of gluinos decaying via stop and sbottom in events with b-jets and large missing transverse momentum in ppcollisions at s=13 TeVwith the ATLAS detector. Int J Clin Exp Med 2016. [DOI: 10.1103/physrevd.94.032003] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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45
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Search for single production of vector-like quarks decaying into Wb in pp collisions at [Formula: see text] TeV with the ATLAS detector. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2016; 76:442. [PMID: 28303082 PMCID: PMC5331864 DOI: 10.1140/epjc/s10052-016-4281-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 07/25/2016] [Indexed: 06/06/2023]
Abstract
A search for singly produced vector-like Q quarks, where Q can be either a T quark with charge [Formula: see text] or a Y quark with charge [Formula: see text], is performed in proton-proton collisions recorded with the ATLAS detector at the LHC. The dataset corresponds to an integrated luminosity of 20.3 fb[Formula: see text] and was produced with a centre-of-mass energy of [Formula: see text] TeV. This analysis targets [Formula: see text] decays where the W boson decays leptonically. A veto on massive large-radius jets is used to reject the dominant [Formula: see text] background. The reconstructed Q-candidate mass, ranging from 0.4 to 1.2 TeV, is used in the search to discriminate signal from background processes. No significant deviation from the Standard Model expectation is observed, and limits are set on the [Formula: see text] cross-section times branching ratio. The results are also interpreted as limits on the QWb coupling and the mixing with the Standard Model sector for a singlet T quark or a Y quark from a doublet. T quarks with masses below 0.95 TeV are excluded at 95 % confidence level, assuming a unit coupling and a BR[Formula: see text], whereas the expected limit is 1.10 TeV.
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Appendiceal orifice inflammation is associated with proximal extension of disease in patients with ulcerative colitis. Colorectal Dis 2016; 18:O278-82. [PMID: 27354363 DOI: 10.1111/codi.13435] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Accepted: 04/28/2016] [Indexed: 12/24/2022]
Abstract
AIM Ulcerative colitis (UC) is considered to be a disease of continuous mucosal inflammation extending proximally from the rectum. However, appendiceal orifice inflammation (AOI) is a skip lesion with segments of continuous involvement from the rectum. The aim of this study was to examine the clinical characteristics and clinical course, particularly focused on proximal extension, of UC in patients with AOI. METHOD A retrospective evaluation of patients with UC who underwent total colonoscopy at the Department of Surgical Oncology, The University of Tokyo, from 2004 to 2014. The degree of AOI was graded endoscopically as follows: 0 (no inflammation); 1 (slight oedema); 2 (moderate inflammation); and 3 (marked inflammation). A total of 189 patient records were reviewed retrospectively. The presence of AOI was analysed with regard to the clinical information of each patient, and its association with proximal extension of proctitis or left-sided colitis was evaluated. RESULTS Of 189 patients with UC who underwent total colonoscopy at our institution, 92 were diagnosed with pancolitis, 50 with left-sided colitis and 47 with proctitis. Endoscopic findings of AOI were observed in 26 patients, including 11 (12.0%) with pancolitis, six (12.0%) with left-sided colitis and nine (19.1%) with proctitis. During follow up, proximal extension of the disease occurred in all nine patients with proctitis AOI. CONCLUSION AOI is more frequently observed in patients with proctitis. Our results showed correlations between AOI and subsequent proximal extension of mucosal inflammation in patients with proctitis.
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Charged-particle distributions in pp interactions at [Formula: see text] measured with the ATLAS detector. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2016; 76:403. [PMID: 28280450 PMCID: PMC5321437 DOI: 10.1140/epjc/s10052-016-4203-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 06/12/2016] [Indexed: 05/10/2023]
Abstract
This paper presents measurements of distributions of charged particles which are produced in proton-proton collisions at a centre-of-mass energy of [Formula: see text] and recorded by the ATLAS detector at the LHC. A special dataset recorded in 2012 with a small number of interactions per beam crossing (below 0.004) and corresponding to an integrated luminosity of 160 [Formula: see text] was used. A minimum-bias trigger was utilised to select a data sample of more than 9 million collision events. The multiplicity, pseudorapidity, and transverse momentum distributions of charged particles are shown in different regions of kinematics and charged-particle multiplicity, including measurements of final states at high multiplicity. The results are corrected for detector effects and are compared to the predictions of various Monte Carlo event generator models which simulate the full hadronic final state.
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Search for squarks and gluinos in final states with jets and missing transverse momentum at [Formula: see text] =13 [Formula: see text]with the ATLAS detector. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2016; 76:392. [PMID: 28747849 PMCID: PMC5501190 DOI: 10.1140/epjc/s10052-016-4184-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 06/08/2016] [Indexed: 05/30/2023]
Abstract
A search for squarks and gluinos in final states containing hadronic jets, missing transverse momentum but no electrons or muons is presented. The data were recorded in 2015 by the ATLAS experiment in [Formula: see text] proton-proton collisions at the Large Hadron Collider. No excess above the Standard Model background expectation was observed in 3.2 [Formula: see text] of analyzed data. Results are interpreted within simplified models that assume R-parity is conserved and the neutralino is the lightest supersymmetric particle. An exclusion limit at the 95 % confidence level on the mass of the gluino is set at 1.51 [Formula: see text] for a simplified model incorporating only a gluino octet and the lightest neutralino, assuming the lightest neutralino is massless. For a simplified model involving the strong production of mass-degenerate first- and second-generation squarks, squark masses below 1.03 [Formula: see text] are excluded for a massless lightest neutralino. These limits substantially extend the region of supersymmetric parameter space excluded by previous measurements with the ATLAS detector.
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Measurement of event-shape observables in [Formula: see text] events in pp collisions at [Formula: see text] [Formula: see text] with the ATLAS detector at the LHC. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2016; 76:375. [PMID: 28280446 PMCID: PMC5321395 DOI: 10.1140/epjc/s10052-016-4176-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 06/02/2016] [Indexed: 06/06/2023]
Abstract
Event-shape observables measured using charged particles in inclusive Z-boson events are presented, using the electron and muon decay modes of the Z bosons. The measurements are based on an integrated luminosity of [Formula: see text] of proton-proton collisions recorded by the ATLAS detector at the LHC at a centre-of-mass energy [Formula: see text] [Formula: see text]. Charged-particle distributions, excluding the lepton-antilepton pair from the Z-boson decay, are measured in different ranges of transverse momentum of the Z boson. Distributions include multiplicity, scalar sum of transverse momenta, beam thrust, transverse thrust, spherocity, and [Formula: see text]-parameter, which are in particular sensitive to properties of the underlying event at small values of the Z-boson transverse momentum. The measured observables are compared with predictions from Pythia 8, Sherpa, and Herwig 7. Typically, all three Monte Carlo generators provide predictions that are in better agreement with the data at high Z-boson transverse momenta than at low Z-boson transverse momenta, and for the observables that are less sensitive to the number of charged particles in the event.
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Search for metastable heavy charged particles with large ionization energy loss in ppcollisions at s=13 TeVusing the ATLAS experiment. Int J Clin Exp Med 2016. [DOI: 10.1103/physrevd.93.112015] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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