73 research outputs found

    Measurements of differential cross-sections in top-quark pair events with a high transverse momentum top quark and limits on beyond the Standard Model contributions to top-quark pair production with the ATLAS detector at √s = 13 TeV

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    Cross-section measurements of top-quark pair production where the hadronically decaying top quark has transverse momentum greater than 355 GeV and the other top quark decays into ℓνb are presented using 139 fb−1 of data collected by the ATLAS experiment during proton-proton collisions at the LHC. The fiducial cross-section at s = 13 TeV is measured to be σ = 1.267 ± 0.005 ± 0.053 pb, where the uncertainties reflect the limited number of data events and the systematic uncertainties, giving a total uncertainty of 4.2%. The cross-section is measured differentially as a function of variables characterising the tt¯ system and additional radiation in the events. The results are compared with various Monte Carlo generators, including comparisons where the generators are reweighted to match a parton-level calculation at next-to-next-to-leading order. The reweighting improves the agreement between data and theory. The measured distribution of the top-quark transverse momentum is used to search for new physics in the context of the effective field theory framework. No significant deviation from the Standard Model is observed and limits are set on the Wilson coefficients of the dimension-six operators OtG and Otq(8), where the limits on the latter are the most stringent to date. [Figure not available: see fulltext.]

    The ATLAS inner detector trigger performance in pp collisions at 13 TeV during LHC Run 2

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    The design and performance of the inner detector trigger for the high level trigger of the ATLAS experiment at the Large Hadron Collider during the 2016-2018 data taking period is discussed. In 2016, 2017, and 2018 the ATLAS detector recorded 35.6 fb(-1), 46.9 fb(-1), and 60.6 fb(-1) respectively of proton-proton collision data at a centre-of-mass energy of 13TeV. In order to deal with the very high interaction multiplicities per bunch crossing expected with the 13TeV collisions the inner detector trigger was redesigned during the long shutdown of the Large Hadron Collider from 2013 until 2015. An overview of these developments is provided and the performance of the tracking in the trigger for the muon, electron, tau and b-jet signatures is discussed. The high performance of the inner detector trigger with these extreme interaction multiplicities demonstrates how the inner detector tracking continues to lie at the heart of the trigger performance and is essential in enabling the ATLAS physics programme

    Measurement of differential cross sections of isolated-photon plus heavy-flavour jet production in pp collisions at √s=8 TeV using the ATLAS detector

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    This Letter presents the measurement of differential cross sections of isolated prompt photons produced in association with a b-jet or a c-jet. These final states provide sensitivity to the heavy-flavour content of the proton and aspects related to the modelling of heavy-flavour quarks in perturbative QCD. The measurement uses proton–proton collision data at a centre-of-mass energy of 8 TeV recorded by the ATLAS detector at the LHC in 2012 corresponding to an integrated luminosity of up to 20.2 fb−1. The differential cross sections are measured for each jet flavour with respect to the transverse energy of the leading photon in two photon pseudorapidity regions: |ηγ | < 1.37 and 1.56 < |ηγ | < 2.37. The measurement covers photon transverse energies 25 < Eγ T < 400 GeV and 25 < Eγ T < 350 GeV respectively for the two |ηγ | regions. For each jet flavour, the ratio of the cross sections in the two |ηγ | regions is also measured. The measurement is corrected for detector effects and compared to leading-order and nextto-leading-order perturbative QCD calculations, based on various treatments and assumptions about the heavy-flavour content of the proton. Overall, the predictions agree well with the measurement, but some deviations are observed at high photon transverse energies. The total uncertainty in the measurement ranges between 13% and 66%, while the central γ + b measurement exhibits the smallest uncertainty, ranging from 13% to 27%, which is comparable to the precision of the theoretical predictions

    Assessment of regional air quality resulting from emission control in the Pearl River Delta region, southern China

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    Title on author’s file: "Assessment of regional air quality resulting from emission control in the Pearl River Delta in China"202308 bcchAccepted ManuscriptOthersGuangdong Province Science and Technology Plan; National Natural Science Foundation of China; Ministry of Science and Technology of the People's Republic of China; National Science and Technology Planning Project; Science and technology innovative research team plan of Guangdong Meteorological BureauPublishe

    中国成年人气流受限与主要慢性病发病风险的前瞻性关联分析 [Associations between airflow obstruction and the risks of morbidity on major chronic diseases in Chinese adults: a prospective cohort study]

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    Objective: To examine the prospective associations between airflow obstruction (AFO) and risks of major chronic diseases morbidity in Chinese adults. Methods: Samples of this study were from the China Kadoorie Biobank. A total of 486 996 participants aged 30 to 79 years (mean 51.5 years) at the baseline study, were included after excluding those who self-reported of having heart disease, stroke and cancer at baseline. AFO was defined under the Global Initiative on Obstructive Lung Disease (GOLD) criteria and forced expiratory volume per one second in percentage of the expected one (FEV(1)% P). Cox regression models were used to investigate the associations of AFO with incidence rates of ischemic heart disease, cerebrovascular disease and lung cancer after adjusted for potential confounders. Results: Over a period of 7 years through the follow-up program, the incident cases of ischemic heart disease, cerebrovascular disease and lung cancer appeared as 24 644, 36 336 and 3 218, respectively. Compared with people without AFO, the HR (95% CI) of GOLD-1 to GOLD-4 were 0.89 (0.78-1.01), 1.05 (0.98-1.12), 1.29 (1.18-1.40) and 1.65 (1.42-1.91) respectively for ischemic heart disease. The HR (95%CI) of GOLD-1 to GOLD-4 were 0.96 (0.70-1.26), 1.12 (0.96-1.31), 1.38 (1.14-1.65) and 1.48 (1.05-2.02) respectively for lung cancer. No statistically significant differences in the associations between GOLD level and cerebrovascular disease morbidity were found. However, each 10% decrease in FEV(1)% P was associated with 7.2% (95%CI: 6.4%-8.0%), 3.6% (95%CI: 3.0%-4.3%) and 10.5% (95%CI: 8.4%-12.6%) increased the risks of ischemic heart disease, cerebrovascular disease and lung cancer respectively. The results were persistant when stratified by smoking status. Conclusion: Higher degree of AFO seemed to be associated with the risks of ischemic heart disease, cerebrovascular disease and lung cancer morbidity among the Chinese adults

    中国成年人气流受限与主要慢性病发病风险的前瞻性关联分析 [Associations between airflow obstruction and the risks of morbidity on major chronic diseases in Chinese adults: a prospective cohort study]

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    Objective: To examine the prospective associations between airflow obstruction (AFO) and risks of major chronic diseases morbidity in Chinese adults. Methods: Samples of this study were from the China Kadoorie Biobank. A total of 486 996 participants aged 30 to 79 years (mean 51.5 years) at the baseline study, were included after excluding those who self-reported of having heart disease, stroke and cancer at baseline. AFO was defined under the Global Initiative on Obstructive Lung Disease (GOLD) criteria and forced expiratory volume per one second in percentage of the expected one (FEV(1)% P). Cox regression models were used to investigate the associations of AFO with incidence rates of ischemic heart disease, cerebrovascular disease and lung cancer after adjusted for potential confounders. Results: Over a period of 7 years through the follow-up program, the incident cases of ischemic heart disease, cerebrovascular disease and lung cancer appeared as 24 644, 36 336 and 3 218, respectively. Compared with people without AFO, the HR (95% CI) of GOLD-1 to GOLD-4 were 0.89 (0.78-1.01), 1.05 (0.98-1.12), 1.29 (1.18-1.40) and 1.65 (1.42-1.91) respectively for ischemic heart disease. The HR (95%CI) of GOLD-1 to GOLD-4 were 0.96 (0.70-1.26), 1.12 (0.96-1.31), 1.38 (1.14-1.65) and 1.48 (1.05-2.02) respectively for lung cancer. No statistically significant differences in the associations between GOLD level and cerebrovascular disease morbidity were found. However, each 10% decrease in FEV(1)% P was associated with 7.2% (95%CI: 6.4%-8.0%), 3.6% (95%CI: 3.0%-4.3%) and 10.5% (95%CI: 8.4%-12.6%) increased the risks of ischemic heart disease, cerebrovascular disease and lung cancer respectively. The results were persistant when stratified by smoking status. Conclusion: Higher degree of AFO seemed to be associated with the risks of ischemic heart disease, cerebrovascular disease and lung cancer morbidity among the Chinese adults

    多重解析地址选择页面 [Associations between family history of major chronic diseases and healthy lifestyles in Chinese adults]

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    Objective: To examine the associations between family history of major chronic diseases and healthy lifestyle in adults in China. Methods: Data were from the baseline and second survey of China Kadoorie Biobank study, which were conducted during 2004-2008 and 2013-2014, respectively. After excluding participants with self-reported histories of coronary heart disease, stroke, cancer or diabetes, a total of 461 213 adults from baseline survey and 20 583 adults from second survey were included in the current study. Participants who reported a family history of acute myocardial infarction, stroke, cancer, or diabetes of any first-degree relative (i.e., biological father, mother, or siblings) were defined as having a family history of major chronic diseases. Healthy lifestyles were defined as current nonsmoking, non-excessive alcohol drinking, eating vegetables and fruits daily, upper quarter of physical activity level, body mass index (BMI) of (18.5-23.9) kg/m(2), and waist- to-hip ratio (WHR) &lt;0.90 (man)/&lt;0.85 (women). Results: At baseline survey, 36.5% of the participants had family history of major chronic diseases. Proportions of the above six healthy lifestyles were 70.5%, 93.0%, 18.0%, 25.0%, 53.4%, and 43.5%, respectively. Compared with participants without family history, the proportions of current nonsmoking, non-excessive drinking, normal BMI, and normal WHR were lower in participants with family history of major chronic diseases, while the proportions of eating vegetables and fruits daily, and being physically active, were higher. In general, the absolute differences in these proportions between participants with and without a family history were only slight. Similar results were observed when other family history status (the type or number of disease, the category or number of affected family members) were analysed. The association between family history of major chronic diseases and healthy lifestyles was consistently observed in the second survey 10 years later. Conclusion: In Chinese population, adults with family history of major chronic diseases did not adopt healthier lifestyles.</p

    Epidemiological characteristics of domestic fuel use in adults in 10 regions of China

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    Objective: To describe the characteristics of cooking and heating fuel use in participants from the China Kadoorie Biobank (CKB) study. Methods: The CKB study recruited 512 891 adults from 10 areas in China during 2004-2008. Information on cooking fuel and heating fuel was collected using a questionnaire in baseline survey. The proportions of various fuels used in different areas, in different populations, and at different time points were calculated and compared. Results: Overall, 52.1% participants used solid fuel for cooking or heating. Rural areas had higher prevalence of solid fuel use than urban areas. The percentage of participants using solid fuel for cooking was 36.1% (coal 20.1%, wood/charcoal 16.0%); The percentage of participants using solid fuel for heating was 36.7% (coal 22.7%, wood/charcoal 14.0%). The prevalence of solid fuel use and the fuel type mainly used varied widely across 10 areas. The proportion of clean fuel use was lower in less-educated and lower-income people. Household coal and wood/charcoal use showed a declining trend, which was more remarkable in urban areas. Conclusion: There are still a large number of rural residents and people with low income relying on solid fuel in China, which is a serious public health concern

    [Association between the frequency of bowel movements and the risk of colorectal cancer in Chinese adults].

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    Objective: To examine the association between the frequencies of bowel movement (BMF) and the risk of colorectal cancer (CRC). Methods: In this study, 510 134 participants from the China Kadoorie Biobank (CKB) were included, after excluding those who reported as having been diagnosed with cancer at the baseline survey. The baseline survey was conducted from June 2004 to July 2008. The present study included data from baseline and follow-up until December 31, 2016. We used the Cox proportional hazards regression models to estimate the HR and the 95%CI of incident CRC with BMF. Results: During an average follow-up period of 9.9 years, 3 056 participants were documented as having developed colorectal cancer. In the site-specific analysis, 1 548 colon cancer and 1 475 rectal cancer were included. Compared with participants who had bowel movements on the daily base, the multivariable-adjusted HR (95%CI) for those who had more than once of BMF were 1.24 (1.12-1.39) for CRC, 1.12 (0.95-1.31) for colon cancer, and 1.37 (1.18-1.59) for rectal cancer. We further examined the association between BMF and CRC, according to the stages of follow-up, the corresponding HR (95%CI) for CRC, colon and rectal cancer were 1.59 (1.36-1.86), 1.43 (1.14- 1.80), and 1.76 (1.41-2.19) for the first five years, while such associations became statistically insignificant in the subsequent follow-up (P for all interactions were &lt;0.05), as time went on. As for CRC, colon or rectal cancers among participants who had lower bowel movements, the risks were not significantly different from those who had bowel movements everyday. Conclusions: Participants who had BMF more than once a day, appeared an increased risk of CRC in the subsequent five years. Since abnormal increase of bowel movements is easily recognizable, programs should be set up on health self- management and early screening for CRC
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