Search for dark matter produced in association with a leptonically decaying Z boson in proton-proton collisions at s = 13 Te

A search for dark matter particles is performed using events with a Z boson candidate and large missing transverse momentum. The analysis is based on proton-proton collision data at a center-of-mass energy of 13Te , collected by the CMS experiment at the LHC in 2016-2018, corresponding to an integrated luminosity of 137fb - 1 . The search uses the decay channels Z → e e and Z → μ μ . No significant excess of events is observed over the background expected from the standard model. Limits are set on dark matter particle production in the context of simplified models with vector, axial-vector, scalar, and pseudoscalar mediators, as well as on a two-Higgs-doublet model with an additional pseudoscalar mediator. In addition, limits are provided for spin-dependent and spin-independent scattering cross sections and are compared to those from direct-detection experiments. The results are also interpreted in the context of models of invisible Higgs boson decays, unparticles, and large extra dimensions.

Right ventricular morphology and function analysis in moderately preterm-born young adults

Background

Previous studies have shown that prematurity leads to altered right ventricular (RV) geometry and performance with persistent impairments in RV systolic function in young adulthood. It is unknown to what extent pulmonary physiology impacts these findings.

Purpose

To better quantify known alterations in RV morphology and function in preterm-born young adults and to determine to what extent these changes are influenced by the pulmonary circulation.

Methods

A total of 101 normotensive preterm-born (n=47, mean gestational age 32.8±3.2 weeks) and term-born (n=54) young adults were recruited. Echocardiography and cardiovascular magnetic resonance (CMR) imaging were performed to characterise RV morphology, RV function, pulmonary hemodynamics and RV-pulmonary arterial vascular (PA) coupling. CMR cine images were used to create a 3D computational atlas of the RV geometry and principal component analysis was undertaken to identify the key modes of shape variation. Spirometry was performed to assess lung function.

Results

RV CMR revealed a higher absolute and indexed RV mass (P<0.05) and lower ejection fraction (54.90±5.17 versus 57.48±4.39%, P=0.008) in young adults born preterm. RV end-diastolic areas and volumes for CMR and echocardiography were lower in preterm-born compared to term-born young adults (P≤0.001). Principal component analysis of the computational atlas defined the anatomical modes of the RV geometry, with mode 1 accounting for 25.3% of the population variance. Preterm and term cohorts showed significant differences (P<0.001) in mode 1, which represented a smaller and shorter RV cavity in the preterm group (Figure 1). Measurements of RV function by echocardiography, including RV fractional area of change (FAC) and tricuspid annular plane systolic excursion (TAPSE), were lower in preterm-born compared to term-born adults (P<0.05). Despite lower pulmonary artery acceleration times (PAAT) in those born preterm (141.1±15.1 versus 159.2±21.6msec, P<0.001), indicating increased pulmonary vascular resistance, the RV remained coupled to its pulmonary circulation (TAPSE/PAAT: 0.13±0.02 versus 0.14±0.03m/sec, P=0.153). Reduced RV performance in preterm-born individuals remained significant when adjusting for pulmonary function parameters (P<0.05).

Conclusions

Multimodality cardiac imaging demonstrated that moderately preterm-born young adults exhibit structural and functional RV alterations, independent of lung physiology. Their RV remains hemodynamically coupled to its pulmonary circulation despite higher RV afterload, lower RV function and altered morphology.

Figure 1. Statistical shape model of the RV

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): British Heart Foundation

Role of optimization algorithms based fuzzy controller in achieving induction motor performance enhancement

Three-phase induction motors (TIMs) are widely used for machines in industrial operations. As an accurate and robust controller, fuzzy logic controller (FLC) is crucial in designing TIMs control systems. The performance of FLC highly depends on the membership function (MF) variables, which are evaluated by heuristic approaches, leading to a high processing time. To address these issues, optimisation algorithms for TIMs have received increasing interest among researchers and industrialists. Here, we present an advanced and efficient quantum-inspired lightning search algorithm (QLSA) to avoid exhaustive conventional heuristic procedures when obtaining MFs. The accuracy of the QLSA based FLC (QLSAF) speed control is superior to other controllers in terms of transient response, damping capability and minimisation of statistical errors under diverse speeds and loads. The performance of the proposed QLSAF speed controller is validated through experiments. Test results under different conditions show consistent speed responses and stator currents with the simulation results.

Though optimization algorithms for fuzzy logic controller (FIC)-based three-phase induction motor (TIM) systems are attractive for improving efficiency, existing methods have limited search capability. Here, the authors report a quantum-inspired lightning search algorithm with enhanced performance.

Hypochlorous acid-generating electrochemical scaffold eliminates Candida albicans biofilms

AIMS

Wound infections involving Candida albicans can be challenging to treat because of the fungus' ability to penetrate wound tissue and form biofilms. The goal of this study was to assess the activity of a hypochlorous acid (HOCl)-generating electrochemical scaffold (e-scaffold) against C. albicans biofilms in vitro and on porcine dermal explants (ex vivo).

METHODS AND RESULTS

C. albicans biofilms were grown either on acrylic-bottom six-well plates (in vitro) or on skin tissue excised from porcine ears (ex vivo), and the polarized e-scaffold was used to generate a continuous supply of low concentration HOCl near biofilm surfaces. C. albicans biofilms grown in vitro were reduced to undetectable amounts within 24 h of e-scaffold exposure, unlike control biofilms (5·28 ± 0·034 log₁₀  (CFU cm^{- 2} ); P < 0·0001). C. albicans biofilms grown on porcine dermal explants were also reduced to undetectable amounts in 24 h, unlike control explant biofilms (4·29 ± 0·057 log₁₀ (CFU cm^{- 2} ); P < 0·0001). There was a decrease in the number of viable mammalian cells (35·6 ± 6·4%) in uninfected porcine dermal explants exposed to continuous HOCl-generating e-scaffolds for 24 h compared to explants exposed to nonpolarized e-scaffolds (not generating HOCl) (P < 0·05).

CONCLUSIONS

Our HOCl-generating e-scaffold is a potential antifungal-free strategy to treat C. albicans biofilms in chronic wounds.

SIGNIFICANCE AND IMPACT OF THE STUDY

Wound infections caused by C. albicans are difficult to treat due to presence of biofilms in wound beds. Our HOCl producing e-scaffold provides a promising novel approach to treat wound infections caused by C. albicans.

Geopolymer Mix in Accordance to Design of Experiment (DOE) Method

This paper presents an experimental study conducted to assess the capability of using DOE method to achieve particular targeted strength for geopolymer concrete. Targeted strength of 30 MPa, 40 MPa and 60 MPa were used in this study. Cube samples with dimension of 100 mm were used for compressive strength test. Similar DOE method calculation as in normal concrete mix were calculated for all the raw material ratios in geopolymer concrete mix. Parameters such as characteristic strength, standard deviation (s), margin (m), target mean strength (fm), free-water/cement ratio (w/c), slump, relative density of aggregate (SSD), concrete density (D), percentage grading of fine aggregate passing 600 μm sieve, and proportion of fine aggregate were determined according to the respective concrete mix design. However, only characteristic strength, fm and w/c varied in each targeted strength mix design while the other parameters were kept constant. In order to yield geopolymer concrete, the used of cement and water in DOE form were fully substituted with the used of fly ash and alkaline activator respectively. Final strength gained from test result for the respective 30 MPa, 40 MPa and 60 MPa were 74.6 MPa, 84.5 MPa and 97.7 MPa. Therefore, it was noted that geopolymer mix yielded higher strength compared to the targeted strength by using the DOE method calculation.

A spatial neighborhood methodology for computing and analyzing lymph node carcinoma similarity in precision medicine

Precision medicine seeks to tailor therapy to the individual patient, based on statistical correlates from patients who are similar to the one under consideration. These correlates can and should go beyond genetics, and in general, beyond tabular or array data that can be easily represented computationally and compared. For example, in many types of cancer, cancer treatment and toxicity depend in large measure on the spatial disease spread-e.g., metastasizes to regional lymph nodes in head and neck cancer. However, there is currently a lack of methodology for integrating spatial information when considering patient similarity. We present a novel modeling methodology for the comparison of cancer patients within a cohort, based on the spatial spread of the lymph nodes affected in each patient. The method uses a topological map, bigrams, and hierarchical clustering to group patients based on their similarity. We compare this approach against a nonspatial (categorical) similarity approach where patients are binned solely by their affected nodes. We present similarity results on a 582 head and neck cancer patient cohort, along with two visual abstractions for analysis of the results, and we present clinician feedback. Our novel methodology partitions a patient cohort into clinically meaningful groups more susceptible to treatment side-effects. Such spatially-aware similarity approaches can help maximize the effectiveness of each patient's treatment.

P374 Prediction of an adverse cardiovascular response to physical exercise from resting echocardiography imaging in young adults with suboptimal blood pressure

Funding Acknowledgements

British Heart Foundation (BHF) grants (PG/13/58/30397)

Background

Young adults with mildly elevated blood pressure are less likely to engage with physical activity. This may be because early hypertension alters myocardial response to moderate exercise, leading to greater perceived exertion and lower levels of enjoyment. As atrial and ventricular function are closely coupled we investigated whether subclinical atrial changes at rest may identify this myocardial response.

Purpose

To identify whether subclinical changes in left atrial function at rest predict response to exercise by performing left atrial deep-phenotyping in a cohort of young adults with a range of blood pressures.

Methods

Seventy-one full-term born young adults (25.25 ± 5.13 years) were enrolled in the Young Adult Cardiovascular Health sTudy (YACHT) to undergo baseline clinical and cardiovascular phenotyping including detailed blood pressure measurement. Cardiopulmonary exercise testing combined with echocardiography imaging was performed to assess the myocardial response to physical exercise at 40%, 60% and 80% of peak exercise load for all participants. Left ventricular ejection fraction and global longitudinal strain were measured from an apical four chamber view at each exercise load, and resting left atrial phasic function was assessed by conventional and speckle tracking echocardiography from apical four and two chamber views (figure 1).

Results

In this young cohort with a range of blood pressure (120.9 ± 12.96/70.85 ± 9.78 mmHg), resting left atrial reservoir and conduit function, but not left atrial structural measures, showed good correlation with left ventricular ejection fraction and global longitudinal strain during 40%, 60% and 80% of peak exercise. The association between resting left atrial conduit with left ventricular deformation at 60% of peak exercise intensity remained significant when adjusted for age, sex and mean arterial pressure (P = 0.007).

Conclusion

Left atrial phasic function at rest predicts left ventricular responses to physical exercise in this cohort of young adults, which may relate to early subclinical left atrial remodelling in early hypertension. These findings require validation in other cohorts and investigation of whether this exercise limitation can be overcome in young hypertensives.

Abstract P374 Figure 1

Adult liver transplant for hepatocellular carcinoma at Wits Donald Gordon Medical Centre in Johannesburg, South Africa

BACKGROUND

For those with unresectable hepatocellular carcinoma, liver transplantation is considered the treatment of choice. Since 2006, the transplant programme at Wits Donald Gordon Medical Centre (WDGMC) has offered liver transplantation for selected patients with hepatocellular carcinoma. While the number of patients transplanted was small, we are unaware of any published data from Southern Africa describing outcomes in this group of liver transplant recipients. The aim of this study was to describe our experience as a case series.

METHODS

The records of all patients with HCC who underwent deceased donor liver transplantation between April 2006 and March 2018 were reviewed retrospectively. Data were extracted from transplant clinic patient files, histopathology and pathology laboratory reports and an existing database of all liver transplant recipients at WDGMC. Patient survival was calculated from the time of transplant and survival estimates were determined by the Kaplan-Meier method.

RESULTS

Thirty-one liver transplants were reviewed. The most common causes of underlying liver disease were infectious, mostly hepatitis B virus, and diseases of lifestyle including alcoholic/non-alcoholic steatohepatitis. Median age at transplant, 57 years (IQR 44-65 years), was younger than observed internationally, but consistent with reports from Africa. Male recipients predominated, in keeping with published trends. Overall, outcomes were worse than expected but for recipients who were within the University of California at San Francisco (UCSF) criteria for transplantation; survival was comparable to previously published data.

CONCLUSION

Despite limitations, this is the first documented series of patients undergoing liver transplantation for HCC in South Africa and demonstrates that good results can be achieved in appropriately selected patients.

Search for a heavy pseudoscalar boson decaying to a Z and a Higgs boson at s = 13 Te

A search is presented for a heavy pseudoscalar boson A decaying to a Z  boson and a Higgs boson with mass of 125GeV . In the final state considered, the Higgs boson decays to a bottom quark and antiquark, and the Z  boson decays either into a pair of electrons, muons, or neutrinos. The analysis is performed using a data sample corresponding to an integrated luminosity of 35.9fb - 1 collected in 2016 by the CMS experiment at the LHC from proton-proton collisions at a center-of-mass energy of 13Te . The data are found to be consistent with the background expectations. Exclusion limits are set in the context of two-Higgs-doublet models in the A boson mass range between 225 and 1000GeV .

Measurement of the t t ¯ production cross section, the top quark mass, and the strong coupling constant using dilepton events in pp collisions at s = 13 Te

A measurement of the top quark-antiquark pair production cross section σ t t ¯ in proton-proton collisions at a centre-of-mass energy of 13Te is presented. The data correspond to an integrated luminosity of 35.9 fb - 1 , recorded by the CMS experiment at the CERN LHC in 2016. Dilepton events ( e ± μ ∓ ,μ + μ - ,e + e - ) are selected and the cross section is measured from a likelihood fit. For a top quark mass parameter in the simulation ofm t MC = 172.5 Ge the fit yields a measured cross sectionσ t t ¯ = 803 ± 2 (stat) ± 25 (syst) ± 20 (lumi) pb , in agreement with the expectation from the standard model calculation at next-to-next-to-leading order. A simultaneous fit of the cross section and the top quark mass parameter in the powheg simulation is performed. The measured value ofm t MC = 172.33 ± 0.14 (stat) - 0.72 + 0.66 (syst) Ge is in good agreement with previous measurements. The resulting cross section is used, together with the theoretical prediction, to determine the top quark mass and to extract a value of the strong coupling constant with different sets of parton distribution functions.

Search for vector-like quarks in events with two oppositely charged leptons and jets in proton-proton collisions at s = 13 Te

A search for the pair production of heavy vector-like partners T and B of the top and bottom quarks has been performed by the CMS experiment at the CERN LHC using proton-proton collisions ats = 13 Te . The data sample was collected in 2016 and corresponds to an integrated luminosity of 35.9fb - 1 . Final states studied for T T ¯ production include those where one of the T quarks decays via T → t Z and the other via T → b W , t Z , or t H , where H is a Higgs boson. For the B B ¯ case, final states include those where one of the B quarks decays via B → b Z and the other B → t W , b Z , or b H . Events with two oppositely charged electrons or muons, consistent with coming from the decay of a Z boson, and jets are investigated. The number of observed events is consistent with standard model background estimations. Lower limits at 95% confidence level are placed on the masses of the T and B quarks for a range of branching fractions. Assuming 100% branching fractions for T → t Z , and B → b Z , T and B quark mass values below 1280 and 1130Ge , respectively, are excluded.

Measurement of the top quark mass in the all-jets final state at s = 13 TeV and combination with the lepton+jets channel

A top quark mass measurement is performed using 35.9 fb - 1 of LHC proton-proton collision data collected with the CMS detector ats = 13 TeV . The measurement uses the t t ¯ all-jets final state. A kinematic fit is performed to reconstruct the decay of the t t ¯  system and suppress the multijet background. Using the ideogram method, the top quark mass ( m t ) is determined, simultaneously constraining an additional jet energy scale factor ( JSF ). The resulting value ofm t = 172.34 ± 0.20 (stat+JSF) ± 0.70 (syst) GeV is in good agreement with previous measurements. In addition, a combined measurement that uses the t t ¯ lepton+jets and all-jets final states is presented, using the same mass extraction method, and provides an m t measurement of 172.26 ± 0.07 (stat+JSF) ± 0.61 (syst) GeV . This is the first combined m t extraction from the lepton+jets and all-jets channels through a single likelihood function.

Observation of Single Top Quark Production in Association with a Z Boson in Proton-Proton Collisions at sqrt[s]=13 TeV

The observation of single top quark production in association with a Z boson and a quark (tZq) is reported. Events from proton-proton collisions at a center-of-mass energy of 13 TeV containing three charged leptons (either electrons or muons) and at least two jets are analyzed. The data were collected with the CMS detector in 2016 and 2017 and correspond to an integrated luminosity of 77.4fb^{-1}. The increased integrated luminosity, a multivariate lepton identification, and a redesigned analysis strategy improve significantly the sensitivity of the analysis compared to previous searches for tZq production. The tZq signal is observed with a significance well over 5 standard deviations. The measured tZq production cross section is σ(pp→tZq→tℓ^{+}ℓ^{-}q)=111±13(stat)_{-9}^{+11}(syst)  fb, for dilepton invariant masses above 30 GeV, in agreement with the standard model expectation.