Dijet Resonance Search with Weak Supervision Using sqrt[s]=13 TeV pp Collisions in the ATLAS Detector

This Letter describes a search for narrowly resonant new physics using a machine-learning anomaly detection procedure that does not rely on signal simulations for developing the analysis selection. Weakly supervised learning is used to train classifiers directly on data to enhance potential signals. The targeted topology is dijet events and the features used for machine learning are the masses of the two jets. The resulting analysis is essentially a three-dimensional search A→BC, for m_{A}∼O(TeV), m_{B},m_{C}∼O(100  GeV) and B, C are reconstructed as large-radius jets, without paying a penalty associated with a large trials factor in the scan of the masses of the two jets. The full run 2 sqrt[s]=13  TeV pp collision dataset of 139  fb^{-1} recorded by the ATLAS detector at the Large Hadron Collider is used for the search. There is no significant evidence of a localized excess in the dijet invariant mass spectrum between 1.8 and 8.2 TeV. Cross-section limits for narrow-width A, B, and C particles vary with m_{A}, m_{B}, and m_{C}. For example, when m_{A}=3  TeV and m_{B}≳200  GeV, a production cross section between 1 and 5 fb is excluded at 95% confidence level, depending on m_{C}. For certain masses, these limits are up to 10 times more sensitive than those obtained by the inclusive dijet search. These results are complementary to the dedicated searches for the case that B and C are standard model bosons.

CP Properties of Higgs Boson Interactions with Top Quarks in the tt[over ¯]H and tH Processes Using H→γγ with the ATLAS Detector

A study of the charge conjugation and parity (CP) properties of the interaction between the Higgs boson and top quarks is presented. Higgs bosons are identified via the diphoton decay channel (H→γγ), and their production in association with a top quark pair (tt[over ¯]H) or single top quark (tH) is studied. The analysis uses 139  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of sqrt[s]=13  TeV with the ATLAS detector at the Large Hadron Collider. Assuming a CP-even coupling, the tt[over ¯]H process is observed with a significance of 5.2 standard deviations. The measured cross section times H→γγ branching ratio is 1.64_{-0.36}^{+0.38}(stat)_{-0.14}^{+0.17}(sys)  fb, and the measured rate for tt[over ¯]H is 1.43_{-0.31}^{+0.33}(stat)_{-0.15}^{+0.21}(sys) times the Standard Model expectation. The tH production process is not observed and an upper limit on its rate of 12 times the Standard Model expectation is set. A CP-mixing angle greater (less) than 43 (-43)° is excluded at 95% confidence level.

Search for Heavy Higgs Bosons Decaying into Two Tau Leptons with the ATLAS Detector Using pp Collisions at sqrt[s]=13 TeV

A search for heavy neutral Higgs bosons is performed using the LHC Run 2 data, corresponding to an integrated luminosity of 139  fb^{-1} of proton-proton collisions at sqrt[s]=13  TeV recorded with the ATLAS detector. The search for heavy resonances is performed over the mass range 0.2-2.5 TeV for the τ^{+}τ^{-} decay with at least one τ-lepton decaying into final states with hadrons. The data are in good agreement with the background prediction of the standard model. In the M_{h}^{125} scenario of the minimal supersymmetric standard model, values of tanβ>8 and tanβ>21 are excluded at the 95% confidence level for neutral Higgs boson masses of 1.0 and 1.5 TeV, respectively, where tanβ is the ratio of the vacuum expectation values of the two Higgs doublets.

Effects of High-Speed Power Training on Neuromuscular and Gait Functions in Frail Elderly with Mild Cognitive Impairment Despite Blunted Executive Functions: A Randomized Controlled Trial

BACKGROUND

Physical frailty and impaired executive function of the brain show similar pathophysiology. Both of these factors lead to dysfunction of neuromuscular and abilities in elderly. High-speed power training (HSPT) has been determined to have positive effects on neuromuscular function and gait performance, as well as executive function in the elderly.

OBJECTIVES

The purpose of this study was to investigate the effects of 8-week HSPT on neuromuscular, gait and executive functions in frail elderly with mild cognitive impairment (MCI).

DESIGN, SETTING AND PARTICIPANTS

We performed a randomized controlled trial of frail elderly from community and medical center in republic of Korea. Forty-two physically frail elderly with MCI were randomly allocated to control (n=22, age=74.22±4.46) and intervention groups (n=18, age=73.77±4.64). The intervention group was subjected to HSPT, 3 times weekly for 8 weeks.

MEASUREMENTS

Isometric contraction of knee extension and flexion with electromyography (EMG) was measured to determine the neuromuscular function such as knee extensor strength, rate of torque development, movement time, pre-motor time, motor time, rate of EMG rise, and hamstrings antagonist co-activation. Additionally, the 4.44-meter gait and timed up-and-go (TUG) test were administered to assess gait performance. A frontal assessment battery was measured in this study.

RESULTS

The 8-week HSPT regimen improved the knee extensor strength from 1.13±0.08 to 1.25±0.07 (p<0.05), the 200-ms RTD from 3.01±0.3 to 3.55±0.24 (p<0.05) and the rate of EMG rise from 166.48±13.31 to 197.94±11.51 (p<0.05), whereas the movement time and motor time were statistically decreased from 921.69±40.10 to 799.51±72.84, and 271.40±19.29 to 181.15±38.08 (p<0.05), respectively. The 4.44-m gait speed and TUG significantly decreased from 6.39±0.25 to 5.5±0.24, and 11.05±0.53 to 9.17±0.43 respectively (p<0.05).

CONCLUSION

The findings of this study suggest the favorable effects of 8-week HSPT on the neuromuscular function and the gait performance in the frail elderly with MCI without increase in the executive function.

Dynamic and stress signatures of the rigid intermediate phase in glass-forming liquids

We study the evolution of enthalpic changes across the glass transition of model sodium silicate glasses (Na₂O)_x(SiO₂)_100-x, focusing on the detection of a flexible-rigid transition and a possible reversibility window in relationship with dynamic properties. We show that the hysteresis resulting from enthalpic relaxation during a numerical cooling-heating cycle is minimized for 12% ≤ x ≤ 20% Na₂O, which echoes with the experimental observation. The key result is the identification of the physical features driving this anomalous behavior. The intermediate-flexible boundary is associated with a dynamic onset with increasing depolymerization that enhances the growing atomic motion with a reduced internal stress, whereas the intermediate-stressed rigid boundary exhibits a substantial increase in the temperature at which the relaxation is maximum. These results suggest an essentially dynamic origin for the intermediate phase observed in network glass-forming liquids.

Measurement of the Lund Jet Plane Using Charged Particles in 13 TeV Proton-Proton Collisions with the ATLAS Detector

The prevalence of hadronic jets at the LHC requires that a deep understanding of jet formation and structure is achieved in order to reach the highest levels of experimental and theoretical precision. There have been many measurements of jet substructure at the LHC and previous colliders, but the targeted observables mix physical effects from various origins. Based on a recent proposal to factorize physical effects, this Letter presents a double-differential cross-section measurement of the Lund jet plane using 139  fb^{-1} of sqrt[s]=13  TeV proton-proton collision data collected with the ATLAS detector using jets with transverse momentum above 675 GeV. The measurement uses charged particles to achieve a fine angular resolution and is corrected for acceptance and detector effects. Several parton shower Monte Carlo models are compared with the data. No single model is found to be in agreement with the measured data across the entire plane.

Effects of atmospheric ammonia on the production performance, serum biochemical indices, and liver RNA-seq data of laying ducks

1. Ammonia is a toxic gas and an air pollutant of great concern. The effects of ammonia-induced damage in ducks are rarely reported. 2. A total of 176 laying ducks were randomly allocated to one of two groups with four replicates and were exposed to ammonia at 5 ± 5 ppm (low ammonia, LA) or 75 ± 5 ppm (high ammonia, HA), respectively, for 30 days. 3. The results showed that atmospheric ammonia exposure significantly decreased body weight and laying performance (P < 0.05). It significantly changed serum biochemical indices by increasing alanine aminotransferase and aspartate aminotransferase (P < 0.05), and decreasing superoxide dismutase activity (P < 0.05). Haematoxylin and eosin staining of hepatocytes revealed severe fatty degeneration. Results of RNA-seq analyses revealed that eight genes were significantly up-regulated in the HA group, which were involved in catalytic activity, single-organism metabolic processes, oxidation-reduction processes, and carbohydrate metabolic processes. 4. These results indicated that atmospheric ammonia exposure reduced production performance, affected serum biochemical indices, and led to severe fatty degeneration in the liver of laying ducks. Differentially expressed genes in liver indicated that there were effects of ammonia exposure on the metabolism and detoxification capabilities in ducks.

Prognostic value of radiologically enlarged lymph nodes in node-negative colon cancer

AIM

Assessment of lymph node (LN) involvement is of crucial importance in the estimation of prognosis and choice of therapeutic options for patients with colon cancer. The relationship between the radiological size of LNs and prognosis in node-negative colon cancer remains uncertain. This study aims to investigate the prognostic impact of radiologically enlarged LNs on the survival of patients with node-negative colon cancer.

METHOD

This retrospective study recruited 395 patients with Stages I and II colon cancer diagnosed between January 2012 and March 2016. Preoperative computed tomography was reviewed for the maximum short-axis diameter of regional LNs, the optimal cutoff value of which was set to 8 mm. The prognostic relevance was analysed in Kaplan-Meier and multivariable Cox proportional hazard regressions.

RESULTS

Patients with tumour in the left colon, TNM Stage II and 12 or more retrieved LNs tended to have radiologically enlarged LNs. Our results suggest that 3-year recurrence-free survival (RFS) and overall survival (OS) were significantly worse in patients with enlarged LNs than those without (RFS 82.8% vs 92.4%, P = 0.026; OS 87.1% vs 95.2%, P = 0.017), which was also confirmed in multivariable analysis [RFS hazard ratio (HR) = 2.192, P = 0.018; OS HR = 3.305, P = 0.010]. Subgroup analysis revealed that in patients with Stage II disease or at least 12 retrieved LNs, radiologically enlarged LN remained an independent predictor of poor RFS and OS.

CONCLUSION

The presence of radiologically enlarged LNs in patients with node-negative colon cancer had an adverse prognosis.

Measurement of Azimuthal Anisotropy of Muons from Charm and Bottom Hadrons in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

The elliptic flow of muons from the decay of charm and bottom hadrons is measured in pp collisions at sqrt[s]=13  TeV using a data sample with an integrated luminosity of 150  pb^{-1} recorded by the ATLAS detector at the LHC. The muons from heavy-flavor decay are separated from light-hadron decay muons using momentum imbalance between the tracking and muon spectrometers. The heavy-flavor decay muons are further separated into those from charm decay and those from bottom decay using the distance-of-closest-approach to the collision vertex. The measurement is performed for muons in the transverse momentum range 4-7 GeV and pseudorapidity range |η|<2.4. A significant nonzero elliptic anisotropy coefficient v_{2} is observed for muons from charm decays, while the v_{2} value for muons from bottom decays is consistent with zero within uncertainties.

Search for Magnetic Monopoles and Stable High-Electric-Charge Objects in 13 Tev Proton-Proton Collisions with the ATLAS Detector

A search for magnetic monopoles and high-electric-charge objects is presented using 34.4  fb^{-1} of 13 TeV pp collision data collected by the ATLAS detector at the LHC during 2015 and 2016. The considered signature is based upon high ionization in the transition radiation tracker of the inner detector associated with a pencil-shape energy deposit in the electromagnetic calorimeter. The data were collected by a dedicated trigger based on the tracker high-threshold hit capability. The results are interpreted in models of Drell-Yan pair production of stable particles with two spin hypotheses (0 and 1/2) and masses ranging from 200 to 4000 GeV. The search improves by approximately a factor of 5 the constraints on the direct production of magnetic monopoles carrying one or two Dirac magnetic charges and stable objects with electric charge in the range 20≤|z|≤60 and extends the charge range to 60<|z|≤100.

Overexpression of HOTTIP promotes proliferation and drug resistance of lung adenocarcinoma by regulating AKT signaling pathway

OBJECTIVE

Lung adenocarcinoma is an important pathological type of lung cancer. Drug resistance is the main reason for failure of lung adenocarcinoma therapy. The purpose of this study is to explore the role of HOTTIP in the progression of lung adenocarcinoma and in drug resistance.

PATIENTS AND METHODS

Differentially expressed lncRNAs in normal lung tissues and lung adenocarcinoma tissues were analyzed in The Cancer Genome Atlas (TCGA) database, followed by analysis of differential lncRNAs in treated sensitive and insensitive groups. HOTTIP was found to be highly expressed in lung adenocarcinoma tissues and in drug-resistant tissues. Next, the expression of HOTTIP in clinical samples and its relation to clinical data were analyzed. Then, we examined the effect of HOTTIP in lung adenocarcinoma by detecting changes in cell proliferation and drug resistance after overexpression and interference with HOTTIP.

RESULTS

By analyzing the normal and lung adenocarcinoma tissues from TCGA database and the treatment of sensitive and insensitive samples, we found that HOTTIP was overexpressed in lung adenocarcinoma and significantly increased in the treatment-insensitive group. Similar results were obtained in clinical samples. In order to explore the role of HOTTIP in lung adenocarcinoma, the proliferation ability of A549 and the drug resistance of A549/PA were significantly reduced after interfering with HOTTIP. Overexpression of HOTTIP, proliferation ability of A549 and drug resistance of A549/PA was significantly enhanced.

CONCLUSIONS

HOTTIP can promote the progression of lung adenocarcinoma, and the formation of lung adenocarcinoma resistance regulated by the protein kinase B (AKT) signaling pathway.

Genotyping and pathogenic characterization of canine distemper virus based on mutations in the hemagglutinin gene in Chinese domestic dogs

Canine distemper virus (CDV) infects wild and domestic Canidae worldwide. The hemag- glutinin (H) gene has the highest genetic variation in the genome of this virus. Thus, the H gene is commonly used for lineage identification and genetic analyses. In order to study the genetic characteristics and pathogenicity of CDV strains prevalent in China, 132 samples were collected from domestic dogs with suspected CDV infection, 58 samples were confirmed to be positive, and the H gene was successfully amplified from 15 samples. The epidemic strain was identified as type Asia-1 and the novel mutations, A51T, V58I, R179K and D262N, were detected in this strain. Isolated strains, BJ16B53, BJ16B14, and BJ17B8, were used for an animal infection experiment in raccoon dogs. BJ16B53 and BJ16B14 were found to cause clinical symptoms, death, and exten- sive lesions in various organs. These results are expected to facilitate the development of effective strategies to monitor and control CDV infection in China.

Observation of Electroweak Production of a Same-Sign W Boson Pair in Association with Two Jets in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

This Letter presents the observation and measurement of electroweak production of a same-sign W boson pair in association with two jets using 36.1  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of sqrt[s]=13  TeV by the ATLAS detector at the Large Hadron Collider. The analysis is performed in the detector fiducial phase-space region, defined by the presence of two same-sign leptons, electron or muon, and at least two jets with a large invariant mass and rapidity difference. A total of 122 candidate events are observed for a background expectation of 69±7 events, corresponding to an observed signal significance of 6.5 standard deviations. The measured fiducial signal cross section is σ^{fid}=2.89_{-0.48}^{+0.51}(stat)_{-0.28}^{+0.29}(syst)  fb.

[Downregulation of Herg1 suppresses osteosarcoma proliferation and invasion by targeting Hippo signaling pathway]

Objective: To detect the effect and regulatory mechanism of human ether à go-go related gene 1 (Herg 1) knockdown on the proliferation and invasion of osteosarcoma (OS). Methods: We constructed a recombinant adenovirus vector (Ad5-Herg1-shRNA) expressing short hair RNA (shRNA) against Herg1 and tested the knockdown efficiency. Then, the effects of Herg 1 knockdown on the proliferation, growth and invasion of osteosarcoma were measured by using cell counting kit-8 (CCK-8), wound healing assay, Transwell assay and xenograft model of nude mice, respectively. Tandem affinity purification, mass spectrometry and dual luciferase reporter assay were used to find out the molecules interacted with Herg1. Western blot was used to detect the expressions of large tumor suppressor gene (LATS1), p-LATS1, Yes-associated protein (YAP) and p-YAP in cells after infection of Ad5-Herg1-shRNA. Results: Compared to Ad5-control-shRNA, Ad5-Herg1-shRNA dramatically inhibited the expression of Herg1 in OS cells. The result of CCK8 array demonstrated that 143B cell vitalities of Ad5-Herg1-shRNA1 and Ad5-Herg1-shRNA2 group were (65.47±3.90)% and (79.90±1.52)%, significantly lower than (100.00±6.14)% of Ad5-control-shRNA group. Meanwhile, U2OS cell vitality of Ad5-Herg1-shRNA1 and Ad5-Herg1-shRNA2 group were (69.69±1.36)% and (76.72±2.75)%, significantly lower than (100.00±3.01)% of Ad5-control-shRNA group (all P<0.001). The results of wound healing array showed that 143B cell migration rates of Ad5-Herg1-shRNA1 and Ad5-Herg1-shRNA2 group were (33.03±2.88)% and (36.47±4.16)%, significantly lower than (97.78±2.28)% of Ad5-control-shRNA group. Meanwhile, U2OS cell migration rates of Ad5-Herg1-shRNA1 and Ad5-Herg1-shRNA2 group were (68.07±0.90)% and (73.97±1.25)%, significantly lower than (96.50±1.12)% of Ad5-control-shRNA group (all P<0.001). The results of Transwell showed that 143B cell invasion numbers of Ad5-Herg1-shRNA1 and Ad5-Herg1-shRNA2 group were 36.50±12.15 and 44.83±7.62, significantly lower than 195.33±19.68 of Ad5-control-shRNA group. Meanwhile, U2OS cell migration rates of Ad5-Herg1-shRNA1 and Ad5-Herg1-shRNA2 group were 21.83±7.99 and 22.85±7.08, significantly lower than 83.33±12.36 of Ad5-control-shRNA group (all P<0.001). The results of xenograft model of OS showed that the tumor volume and weight of Ad5-Herg1-shRNA group were significantly smaller than of Ad5-control-shRNA group after 14 days and 5 weeks of inoculation, respectively (P<0.001). Moreover, knockdown of Herg1 inhibited the metastasis of OS cells. In mechanism, Herg1 protein interacted with NF2 protein. Knockdown of Herg1 significantly suppressed the expression levels of LATS1 and YAP protein, and promoted the phosphorylation of LATS1 and YAP in OS cells (all P<0.001). Conclusion: Our findings suggest that Herg1 participates in the proliferation and motility of OS cells and may serve as a potential therapeutic target for osteosarcoma patients.

Observation of Light-by-Light Scattering in Ultraperipheral Pb+Pb Collisions with the ATLAS Detector

This Letter describes the observation of the light-by-light scattering process, γγ→γγ, in Pb+Pb collisions at sqrt[s_{NN}]=5.02  TeV. The analysis is conducted using a data sample corresponding to an integrated luminosity of 1.73  nb^{-1}, collected in November 2018 by the ATLAS experiment at the LHC. Light-by-light scattering candidates are selected in events with two photons produced exclusively, each with transverse energy E_{T}^{γ}>3  GeV and pseudorapidity |η_{γ}|<2.4, diphoton invariant mass above 6 GeV, and small diphoton transverse momentum and acoplanarity. After applying all selection criteria, 59 candidate events are observed for a background expectation of 12±3 events. The observed excess of events over the expected background has a significance of 8.2 standard deviations. The measured fiducial cross section is 78±13(stat)±7(syst)±3(lumi)  nb.

Comparison of Fragmentation Functions for Jets Dominated by Light Quarks and Gluons from pp and Pb+Pb Collisions in ATLAS

Charged-particle fragmentation functions for jets azimuthally balanced by a high-transverse-momentum, prompt, isolated photon are measured in 25  pb^{-1} of pp and 0.49  nb^{-1} of Pb+Pb collision data at 5.02 TeV per nucleon pair recorded with the ATLAS detector at the Large Hadron Collider. The measurements are compared to predictions of Monte Carlo generators and to measurements of inclusively selected jets. In pp collisions, a different jet fragmentation function in photon-tagged events from that in inclusive jet events arises from the difference in fragmentation between light quarks and gluons. The ratios of the fragmentation functions in Pb+Pb events to that in pp events are used to explore the parton color-charge dependence of jet quenching in the hot medium. In relatively peripheral collisions, fragmentation functions exhibit a similar modification pattern for photon-tagged and inclusive jets. However, photon-tagged jets are observed to have larger modifications than inclusive jets in central Pb+Pb events.

Combination of Searches for Invisible Higgs Boson Decays with the ATLAS Experiment

Dark matter particles, if sufficiently light, may be produced in decays of the Higgs boson. This Letter presents a statistical combination of searches for H→invisible decays where H is produced according to the standard model via vector boson fusion, Z(ℓℓ)H, and W/Z(had)H, all performed with the ATLAS detector using 36.1  fb^{-1} of pp collisions at a center-of-mass energy of sqrt[s]=13  TeV at the LHC. In combination with the results at sqrt[s]=7 and 8 TeV, an exclusion limit on the H→invisible branching ratio of 0.26(0.17_{-0.05}^{+0.07}) at 95% confidence level is observed (expected).

Search for the Production of a Long-Lived Neutral Particle Decaying within the ATLAS Hadronic Calorimeter in Association with a Z Boson from pp Collisions at sqrt[s]=13 TeV

This Letter presents a search for the production of a long-lived neutral particle (Z_{d}) decaying within the ATLAS hadronic calorimeter, in association with a standard model (SM) Z boson produced via an intermediate scalar boson, where Z→ℓ^{+}ℓ^{-} (ℓ=e, μ). The data used were collected by the ATLAS detector during 2015 and 2016 pp collisions with a center-of-mass energy of sqrt[s]=13  TeV at the Large Hadron Collider and correspond to an integrated luminosity of 36.1±0.8  fb^{-1}. No significant excess of events is observed above the expected background. Limits on the production cross section of the scalar boson times its decay branching fraction into the long-lived neutral particle are derived as a function of the mass of the intermediate scalar boson, the mass of the long-lived neutral particle, and its cτ from a few centimeters to one hundred meters. In the case that the intermediate scalar boson is the SM Higgs boson, its decay branching fraction to a long-lived neutral particle with a cτ approximately between 0.1 and 7 m is excluded with a 95% confidence level up to 10% for m_{Z_{d}} between 5 and 15 GeV.

Clinical utility of quantitative dual-energy CT iodine maps and CT morphological features in distinguishing small-cell from non-small-cell lung cancer

AIM

To evaluate the clinical usefulness of quantitative dual-energy (DE) computed tomography (CT) iodine enhancement metrics combined with morphological CT features in distinguishing small-cell lung cancer (SCLC) from non-small-cell lung cancer (NSCLC).

MATERIALS AND METHODS

One hundred and six untreated lung cancer patients who underwent DECT before biopsy or surgery were prospectively enrolled. Twenty-seven routine CT descriptors, including tumour location, size, shape, margin, enhancement heterogeneity, and internal and surrounding structures, and associated findings were assessed and DECT parameters were measured in all patients. Multiple logistic regression analyses were applied to identify independent predictors of SCLC. The area under the receiver operating characteristic curve was compared between CT features combined with DECT metrics and CT features alone for distinguishing SCLC from NSCLC.

RESULTS

Histology revealed NSCLC in 80 and SCLC in 26 patients. In univariate analysis, 12 morphological CT features and two DECT metrics differed significantly between NSCLC and SCLC. When DECT parameters were combined with CT features for multivariate analysis, the independent predictors of SCLC were large tumour size, central location, confluent mediastinal lymphadenopathy, homogeneous enhancement, absence of coarse spiculation, and lower iodine density and iodine ratio (all p<0.05). The area under the receiver operating characteristic curve was improved from 0.908 to 0.981 after adding DECT metrics compared with CT features alone (p=0.007).

CONCLUSION

The combination of DECT measures and CT morphological features can be used to distinguish SCLC from NSCLC, with higher diagnostic performance compared with CT morphological features alone.

Search for doubly charged scalar bosons decaying into same-sign W boson pairs with the ATLAS detector

A search for doubly charged scalar bosons decaying into W boson pairs is presented. It uses a data sample from proton-proton collisions corresponding to an integrated luminosity of 36.1 fb - 1 collected by the ATLAS detector at the LHC at a centre-of-mass energy of 13 TeV in 2015 and 2016. This search is guided by a model that includes an extension of the Higgs sector through a scalar triplet, leading to a rich phenomenology that includes doubly charged scalar bosons H ± ± . Those bosons are produced in pairs in proton-proton collisions and decay predominantly into electroweak gauge bosons H ± ± → W ± W ± . Experimental signatures with several leptons, missing transverse energy and jets are explored. No significant deviations from the Standard Model predictions are found. The parameter space of the benchmark model is excluded at 95% confidence level for H ± ± bosons with masses between 200 and 220 GeV.

Search for Higgs boson pair production in the γ γ W W ∗ channel using pp collision data recorded at s = 13 TeV with the ATLAS detector

Searches for non-resonant and resonant Higgs boson pair production are performed in the γ γ W W ∗ channel with the final state of γ γ ℓ ν j j using 36.1  fb - 1 of proton-proton collision data recorded at a centre-of-mass energy ofs = 13 TeV by the ATLAS detector at the Large Hadron Collider. No significant deviation from the Standard Model prediction is observed. A 95% confidence-level observed upper limit of 7.7 pb is set on the cross section for non-resonant production, while the expected limit is 5.4 pb. A search for a narrow-width resonance X decaying to a pair of Standard Model Higgs bosons HH is performed with the same set of data, and the observed upper limits on σ ( p p → X ) × B ( X → H H ) range between 40.0 and 6.1 pb for masses of the resonance between 260 and 500 GeV, while the expected limits range between 17.6 and 4.4 pb. When deriving the limits above, the Standard Model branching ratios of the H → γ γ and H → W W ∗ are assumed.

[The changes of plasma coagulation function in patients with glioma and its correlation with malignant grade of glioma]

Objective: To investigate the changes of activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time(TT), fibrinogen(FIB) and platelet counts(PLT) in plasma of patients with glioma, and to explore the correlations between PT, APTT, TT, FIB and PLT with malignant grades of glioma. Methods: One hundred and seventy-two patients with glioma and 47 health controls were investigated in a retrospective analysis. All patients were diagnosed and identified the WHO grade by pathologist after operation. Including 40 cases with glioblastoma multiforme, WHO Ⅳ grade, 45 cases with anaplastic astrocytoma, WHO Ⅲ grade, 46 cases with astrocytoma and oligodendroglia astrocytoma, WHO Ⅱ grade, and 41 cases with pilocytic astrocytoma. Results: PT was significantly shorter in patients with WHO Ⅰ-Ⅳ grade glioma than that in normal controls (P<0.05); APTT was significantly shorter in patients with WHO Ⅲ and Ⅳ grade glioma than that in normal controls and WHO Ⅰ grade glioma patients (P<0.05); FIB of WHO Ⅳ grade glioma was higher than that in normal control and WHO Ⅰ to Ⅲ grade glioma (P<0.05). While, there was no significant difference of TT and PLT among patients with WHO Ⅰ to Ⅳ and normal controls (P>0.05). Spearman correlation analysis showed that there was negative correlation between APTT and WHO grade (r=-0.200, P=0.007) as well as positive correlation between FIB and WHO grade (r=0.175, P=0.020); Pearson linear correlation analysis showed that there was negative correlation between APTT and Ki67 in patients with glioma. Conclusions: the levels of FIB and APTT in patients with glioma were correlated with WHO grade of glioma, and higher FIB, shorter APTT and PT in patients with WHO Ⅳ grade glioma indicated that there exist hypercoagulation states.

Measurement of the azimuthal anisotropy of charged particles produced in s NN = 5.02 TeV Pb+Pb collisions with the ATLAS detector

Measurements of the azimuthal anisotropy in lead-lead collisions ats NN = 5.02 TeV are presented using a data sample corresponding to 0.49nb - 1 integrated luminosity collected by the ATLAS experiment at the LHC in 2015. The recorded minimum-bias sample is enhanced by triggers for "ultra-central" collisions, providing an opportunity to perform detailed study of flow harmonics in the regime where the initial state is dominated by fluctuations. The anisotropy of the charged-particle azimuthal angle distributions is characterized by the Fourier coefficients, v 2 - v 7 , which are measured using the two-particle correlation, scalar-product and event-plane methods. The goal of the paper is to provide measurements of the differential as well as integrated flow harmonics v n over wide ranges of the transverse momentum, 0.5  < p T <  60 GeV, the pseudorapidity, | η | <  2.5, and the collision centrality 0-80%. Results from different methods are compared and discussed in the context of previous and recent measurements in Pb+Pb collisions ats NN = 2.76  TeV and 5.02  TeV . In particular, the shape of the p T dependence of elliptic or triangular flow harmonics is observed to be very similar at different centralities after scaling the v n and p T values by constant factors over the centrality interval 0-60% and the p T range 0.5  < p T <  5 GeV.

Operation and performance of the ATLAS Tile Calorimeter in Run 1

The Tile Calorimeter is the hadron calorimeter covering the central region of the ATLAS experiment at the Large Hadron Collider. Approximately 10,000 photomultipliers collect light from scintillating tiles acting as the active material sandwiched between slabs of steel absorber. This paper gives an overview of the calorimeter's performance during the years 2008-2012 using cosmic-ray muon events and proton-proton collision data at centre-of-mass energies of 7 and 8 TeV with a total integrated luminosity of nearly 30 fb - 1 . The signal reconstruction methods, calibration systems as well as the detector operation status are presented. The energy and time calibration methods performed excellently, resulting in good stability of the calorimeter response under varying conditions during the LHC Run 1. Finally, the Tile Calorimeter response to isolated muons and hadrons as well as to jets from proton-proton collisions is presented. The results demonstrate excellent performance in accord with specifications mentioned in the Technical Design Report.

Combination of the Searches for Pair-Produced Vectorlike Partners of the Third-Generation Quarks at sqrt[s]=13 TeV with the ATLAS Detector

A combination of the searches for pair-produced vectorlike partners of the top and bottom quarks in various decay channels (T→Zt/Wb/Ht, B→Zb/Wt/Hb) is performed using 36.1  fb^{-1} of pp collision data at sqrt[s]=13  TeV with the ATLAS detector at the Large Hadron Collider. The observed data are found to be in good agreement with the standard model background prediction in all individual searches. Therefore, combined 95% confidence-level upper limits are set on the production cross section for a range of vectorlike quark scenarios, significantly improving upon the reach of the individual searches. Model-independent limits are set assuming the vectorlike quarks decay to standard model particles. A singlet T is excluded for masses below 1.31 TeV and a singlet B is excluded for masses below 1.22 TeV. Assuming a weak isospin (T,B) doublet and |V_{Tb}|≪|V_{tB}|, T and B masses below 1.37 TeV are excluded.

Observation of Centrality-Dependent Acoplanarity for Muon Pairs Produced via Two-Photon Scattering in Pb+Pb Collisions at sqrt[s_{NN}]=5.02 TeV with the ATLAS Detector

This Letter presents a measurement of γγ→μ^{+}μ^{-} production in Pb+Pb collisions recorded by the ATLAS detector at the Large Hadron Collider at sqrt[s_{NN}]=5.02  TeV with an integrated luminosity of 0.49  nb^{-1}. The azimuthal angle and transverse momentum correlations between the muons are measured as a function of collision centrality. The muon pairs are produced from γγ through the interaction of the large electromagnetic fields of the nuclei. The contribution from background sources of muon pairs is removed using a template fit method. In peripheral collisions, the muons exhibit a strong back-to-back correlation consistent with previous measurements of muon pair production in ultraperipheral collisions. The angular correlations are observed to broaden significantly in central collisions. The modifications are qualitatively consistent with rescattering of the muons while passing through the hot matter produced in the collision.

Pulmonary thromboendarterectomy is a curative resolution for chronic thromboembolic pulmonary hypertension associated with antiphospholipid syndrome: a retrospective cohort study

Background

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare and life-threatening condition with poor prognosis in patients with antiphospholipid syndrome (APS). Pulmonary thromboendarterectomy (PTE) is the optimal surgical option for CTEPH.

Objectives

This retrospective cohort study aimed to evaluate the efficacy and risk of PTE in patients with APS-associated CTEPH.

Methods

Consecutive patients with APS-associated CTEPH diagnosed between January 2012 and September 2017 at Peking Union Medical College Hospital were retrospectively evaluated. Demographics, clinical manifestations, antiphospholipid antibody (aPL) profiles, and pulmonary arterial hypertension–targeted medications were collected. Deterioration of cardiac function and death were chosen as the endpoints, in order to assess the effect of PTE on short-term and long-term prognoses (evaluated by the change of cardiac function after treatment and cardiac deterioration or death in the follow-up, respectively).

Results

A total of 20 patients with APS-associated CTEPH were enrolled, and eight patients underwent PTE. Chi-square test ( p = 0.01) and Kaplan–Meier curves (log rank test, p = 0.04) showed that there were statistically significant differences in both short-term and long-term prognoses between patients with and without PTE.

Conclusion

These results provide strong evidence that PTE is a curative resolution in patients with APS-associated CTEPH. Following a full specialized and multidisciplinary risk-benefit evaluation to limit the risk of thrombosis or bleeding and to manage possible thrombocytopenia, PTE is at least a temporal curative resolution for CTEPH complicated with APS.

Search for Resonant and Nonresonant Higgs Boson Pair Production in the bb[over ¯]τ^{+}τ^{-} Decay Channel in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

A search for resonant and nonresonant pair production of Higgs bosons in the bb[over ¯]τ^{+}τ^{-} final state is presented. The search uses 36.1  fb^{-1} of pp collision data with sqrt[s]=13  TeV recorded by the ATLAS experiment at the LHC in 2015 and 2016. Decays of the τ-lepton pairs with at least one τ lepton decaying to final states with hadrons and a neutrino are considered. No significant excess above the expected background is observed in the data. The cross-section times branching ratio for nonresonant Higgs boson pair production is constrained to be less than 30.9 fb, 12.7 times the standard model expectation, at 95% confidence level. The data are also analyzed to probe resonant Higgs boson pair production, constraining a model with an extended Higgs sector based on two doublets and a Randall-Sundrum bulk graviton model. Upper limits are placed on the resonant Higgs boson pair production cross-section times branching ratio, excluding resonances X in the mass range 305  GeV<m_{X}<402  GeV in the simplified hMSSM minimal supersymmetric model for tanβ=2 and excluding bulk Randall-Sundrum gravitons G_{KK} in the mass range 325  GeV<m_{G_{KK}}<885  GeV for k/M[over ¯]_{Pl}=1.

Suppression of microRNA-101 attenuates hypoxia-induced myocardial H9c2 cell injury by targeting DIMT1-Sp1/survivin pathway

OBJECTIVE

MicroRNAs (miRNAs) are small single-stranded RNAs in eukaryotic cells, which play important regulatory roles in the pathogenesis of various diseases. We aimed to investigate the effects of miRNA-101 (miR-101) on hypoxia-induced myocardial infarction (MI) cell injury model (myocardial H9c2 cell injury model). The possible target gene of miR-101 was also analyzed.

MATERIALS AND METHODS

H9c2 cells were exposed to hypoxia treatment. Cell viability, migration, invasion, apoptosis and the expression of miR-101 were detected using CCK-8 assay, transwell assay, flow cytometer analysis, Western blotting and qRT-PCR, respectively. Then, the effects of miR-101 overexpression or suppression on the cell injury induced by hypoxia were assessed. Dual luciferase reporter assay was used to analyze the possible target gene of miR-101. Finally, the effects of dimethyladenosine transferase 1 homolog (DIMT1), the possible target gene of miR-101, on H9c2 cell injury were investigated.

RESULTS

Hypoxia significantly induced H9c2 cell injury. miR-101 was up-regulated after hypoxia induction. Hypoxia-induced cell injury was significantly reversed by miR-101 suppression and exacerbated by miR-101 overexpression. DIMT1 was a direct target gene of miR-101. Knockdown of DIMT1 markedly inhibited the protective effects of miR-101 suppression on hypoxia-induced cell injury by suppressing specific protein 1 (Sp1)/Survivin pathway.

CONCLUSIONS

We verified the critical roles of miR-101 in regulating myocardial cell injury induced by hypoxia. DIMT1-mediated the Sp1/Survivin pathway was also involved in this process. Our findings replenished the understanding of the regulatory roles of miRNAs in hypoxia-induced MI cell injury and provided new molecular target for therapy and diagnosis of MI.

Measurement of colour flow using jet-pull observables in t t ¯ events with the ATLAS experiment at s = 13 TeV

Previous studies have shown that weighted angular moments derived from jet constituents encode the colour connections between partons that seed the jets. This paper presents measurements of two such distributions, the jet-pull angle and jet-pull magnitude, both of which are derived from the jet-pull angular moment. The measurement is performed in t t ¯ events with one leptonically decaying W boson and one hadronically decaying W boson, using 36.1 fb - 1 of pp collision data recorded by the ATLAS detector ats = 13 TeV delivered by the Large Hadron Collider. The observables are measured for two dijet systems, corresponding to the colour-connected daughters of the W boson and the two b-jets from the top-quark decays, which are not expected to be colour connected. To allow the comparison of the measured distributions to colour model predictions, the measured distributions are unfolded to particle level, after correcting for experimental effects introduced by the detector. While good agreement can be found for some combinations of predictions and observables, none of the predictions describes the data well across all observables.

Probing the Quantum Interference between Singly and Doubly Resonant Top-Quark Production in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

This Letter presents a normalized differential cross-section measurement in a fiducial phase-space region where interference effects between top-quark pair production and associated production of a single top quark with a W boson and a b-quark are significant. Events with exactly two leptons (ee, μμ, or eμ) and two b-tagged jets that satisfy a multiparticle invariant mass requirement are selected from 36.1  fb^{-1} of proton-proton collision data taken at sqrt[s]=13  TeV with the ATLAS detector at the LHC in 2015 and 2016. The results are compared with predictions from simulations using various strategies for the interference. The standard prescriptions for interference modeling are significantly different from each other but are within 2σ of the data. State-of-the-art predictions that naturally incorporate interference effects provide the best description of the data in the measured region of phase space most sensitive to these effects. These results provide an important constraint on interference models and will guide future model development and tuning.

Prompt and non-prompt J / ψ elliptic flow in Pb+Pb collisions at s NN = 5.02 Tev with the ATLAS detector

The elliptic flow of prompt and non-prompt J / ψ was measured in the dimuon decay channel in Pb+Pb collisions ats NN = 5.02   TeV with an integrated luminosity of 0.42 nb - 1 with the ATLAS detector at the LHC. The prompt and non-prompt signals are separated using a two-dimensional simultaneous fit of the invariant mass and pseudo-proper decay time of the dimuon system from the J / ψ decay. The measurement is performed in the kinematic range of dimuon transverse momentum and rapidity 9 < p T < 30   GeV , | y | < 2 , and 0-60% collision centrality. The elliptic flow coefficient, v 2 , is evaluated relative to the event plane and the results are presented as a function of transverse momentum, rapidity and centrality. It is found that prompt and non-prompt J / ψ mesons have non-zero elliptic flow. Prompt J / ψ v 2 decreases as a function of p T , while for non-prompt J / ψ it is, with limited statistical significance, consistent with a flat behaviour over the studied kinematic region. There is no observed dependence on rapidity or centrality.

Prompt and non-prompt J / ψ and ψ ( 2 S ) suppression at high transverse momentum in 5.02 TeV Pb+Pb collisions with the ATLAS experiment

A measurement of J / ψ and ψ ( 2 S ) production is presented. It is based on a data sample from Pb+Pb collisions at s NN = 5.02 TeV and pp collisions at s = 5.02 TeV recorded by the ATLAS detector at the LHC in 2015, corresponding to an integrated luminosity of 0.42 nb - 1 and 25 pb - 1 in Pb+Pb and pp, respectively. The measurements of per-event yields, nuclear modification factors, and non-prompt fractions are performed in the dimuon decay channel for 9 < p T μ μ < 40 GeV in dimuon transverse momentum, and - 2 < y μ μ < 2 in rapidity. Strong suppression is found in Pb+Pb collisions for both prompt and non-prompt J / ψ , increasing with event centrality. The suppression of prompt ψ ( 2 S ) is observed to be stronger than that of J / ψ , while the suppression of non-prompt ψ ( 2 S ) is equal to that of the non-prompt J / ψ within uncertainties, consistent with the expectation that both arise from b-quarks propagating through the medium. Despite prompt and non-prompt J / ψ arising from different mechanisms, the dependence of their nuclear modification factors on centrality is found to be quite similar.

Search for Low-Mass Dijet Resonances Using Trigger-Level Jets with the ATLAS Detector in pp Collisions at sqrt[s]=13 TeV

Searches for dijet resonances with sub-TeV masses using the ATLAS detector at the Large Hadron Collider can be statistically limited by the bandwidth available to inclusive single-jet triggers, whose data-collection rates at low transverse momentum are much lower than the rate from standard model multijet production. This Letter describes a new search for dijet resonances where this limitation is overcome by recording only the event information calculated by the jet trigger algorithms, thereby allowing much higher event rates with reduced storage needs. The search targets low-mass dijet resonances in the range 450-1800 GeV. The analyzed data set has an integrated luminosity of up to 29.3  fb^{-1} and was recorded at a center-of-mass energy of 13 TeV. No excesses are found; limits are set on Gaussian-shaped contributions to the dijet mass distribution from new particles and on a model of dark-matter particles with axial-vector couplings to quarks.

Search for new phenomena using the invariant mass distribution of same-flavour opposite-sign dilepton pairs in events with missing transverse momentum in s=13 Tepp collisions with the ATLAS detector

A search for new phenomena in final states containing an e + e - or μ + μ - pair, jets, and large missing transverse momentum is presented. This analysis makes use of proton-proton collision data with an integrated luminosity of 36.1 fb - 1 , collected during 2015 and 2016 at a centre-of-mass energy s = 13 TeV with the ATLAS detector at the Large Hadron Collider. The search targets the pair production of supersymmetric coloured particles (squarks or gluinos) and their decays into final states containing an e + e - or μ + μ - pair and the lightest neutralino ( χ ~ 1 0 ) via one of two next-to-lightest neutralino ( χ ~ 2 0 ) decay mechanisms: χ ~ 2 0 → Z χ ~ 1 0 , where the Z boson decays leptonically leading to a peak in the dilepton invariant mass distribution around the Z boson mass; and χ ~ 2 0 → ℓ + ℓ - χ ~ 1 0 with no intermediate ℓ + ℓ - resonance, yielding a kinematic endpoint in the dilepton invariant mass spectrum. The data are found to be consistent with the Standard Model expectation. Results are interpreted using simplified models, and exclude gluinos and squarks with masses as large as 1.85 and 1.3  Te at 95% confidence level, respectively.

Search for heavy particles decaying into top-quark pairs using lepton-plus-jets events in proton-proton collisions at s = 13 TeV with the ATLAS detector

A search for new heavy particles that decay into top-quark pairs is performed using data collected from proton-proton collisions at a centre-of-mass energy of 13  TeV by the ATLAS detector at the Large Hadron Collider. The integrated luminosity of the data sample is 36.1 fb- 1 . Events consistent with top-quark pair production are selected by requiring a single isolated charged lepton, missing transverse momentum and jet activity compatible with a hadronic top-quark decay. Jets identified as likely to contain b-hadrons are required to reduce the background from other Standard Model processes. The invariant mass spectrum of the candidate top-quark pairs is examined for local excesses above the background expectation. No significant deviations from the Standard Model predictions are found. Exclusion limits are set on the production cross-section times branching ratio for hypothetical Z ' bosons, Kaluza-Kein gluons and Kaluza-Klein gravitons that decay into top-quark pairs.