MyMedR

Amivantamab plus Chemotherapy in NSCLC with EGFR Exon 20 Insertions

Zhou C, Tang KJ, Cho BC, Liu B, Paz-Ares L, Cheng S, et al.

N Engl J Med, 2023 Nov 30;389(22):2039-2051.

PMID: 37870976 DOI: 10.1056/NEJMoa2306441

BACKGROUND: Amivantamab has been approved for the treatment of patients with advanced non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) exon 20 insertions who have had disease progression during or after platinum-based chemotherapy. Phase 1 data showed the safety and antitumor activity of amivantamab plus carboplatin-pemetrexed (chemotherapy). Additional data on this combination therapy are needed.

METHODS: In this phase 3, international, randomized trial, we assigned in a 1:1 ratio patients with advanced NSCLC with EGFR exon 20 insertions who had not received previous systemic therapy to receive intravenous amivantamab plus chemotherapy (amivantamab-chemotherapy) or chemotherapy alone. The primary outcome was progression-free survival according to blinded independent central review. Patients in the chemotherapy group who had disease progression were allowed to cross over to receive amivantamab monotherapy.

RESULTS: A total of 308 patients underwent randomization (153 to receive amivantamab-chemotherapy and 155 to receive chemotherapy alone). Progression-free survival was significantly longer in the amivantamab-chemotherapy group than in the chemotherapy group (median, 11.4 months and 6.7 months, respectively; hazard ratio for disease progression or death, 0.40; 95% confidence interval [CI], 0.30 to 0.53; P<0.001). At 18 months, progression-free survival was reported in 31% of the patients in the amivantamab-chemotherapy group and in 3% in the chemotherapy group; a complete or partial response at data cutoff was reported in 73% and 47%, respectively (rate ratio, 1.50; 95% CI, 1.32 to 1.68; P<0.001). In the interim overall survival analysis (33% maturity), the hazard ratio for death for amivantamab-chemotherapy as compared with chemotherapy was 0.67 (95% CI, 0.42 to 1.09; P = 0.11). The predominant adverse events associated with amivantamab-chemotherapy were reversible hematologic and EGFR-related toxic effects; 7% of patients discontinued amivantamab owing to adverse reactions.

CONCLUSIONS: The use of amivantamab-chemotherapy resulted in superior efficacy as compared with chemotherapy alone as first-line treatment of patients with advanced NSCLC with EGFR exon 20 insertions. (Funded by Janssen Research and Development; PAPILLON ClinicalTrials.gov number, NCT04538664.).

Soil Geobacteraceae are the key predictors of neurotoxic methylmercury bioaccumulation in rice

Zhong H, Tang W, Li Z, Sonne C, Lam SS, Zhang X, et al.

Nat Food, 2024 Apr 11.

PMID: 38605129 DOI: 10.1038/s43016-024-00954-7

Contamination of rice by the potent neurotoxin methylmercury (MeHg) originates from microbe-mediated Hg methylation in soils. However, the high diversity of Hg methylating microorganisms in soils hinders the prediction of MeHg formation and challenges the mitigation of MeHg bioaccumulation via regulating soil microbiomes. Here we explored the roles of various cropland microbial communities in MeHg formation in the potentials leading to MeHg accumulation in rice and reveal that Geobacteraceae are the key predictors of MeHg bioaccumulation in paddy soil systems. We characterized Hg methylating microorganisms from 67 cropland ecosystems across 3,600 latitudinal kilometres. The simulations of a rice-paddy biogeochemical model show that MeHg accumulation in rice is 1.3-1.7-fold more sensitive to changes in the relative abundance of Geobacteraceae compared to Hg input, which is recognized as the primary parameter in controlling MeHg exposure. These findings open up a window to predict MeHg formation and accumulation in human food webs, enabling more efficient mitigation of risks to human health through regulations of key soil microbiomes.

Computerized assisted evaluation system for canine cardiomegaly via key points detection with deep learning

Zhang M, Zhang K, Yu D, Xie Q, Liu B, Chen D, et al.

Prev Vet Med, 2021 Aug;193:105399.

PMID: 34118647 DOI: 10.1016/j.prevetmed.2021.105399

Cardiomegaly is the main imaging finding for canine heart diseases. There are many advances in the field of medical diagnosing based on imaging with deep learning for human being. However there are also increasing realization of the potential of using deep learning in veterinary medicine. We reported a clinically applicable assisted platform for diagnosing the canine cardiomegaly with deep learning. VHS (vertebral heart score) is a measuring method used for the heart size of a dog. The concrete value of VHS is calculated with the relative position of 16 key points detected by the system, and this result is then combined with VHS reference range of all dog breeds to assist in the evaluation of the canine cardiomegaly. We adopted HRNet (high resolution network) to detect 16 key points (12 and four key points located on vertebra and heart respectively) in 2274 lateral X-ray images (training and validation datasets) of dogs, the model was then used to detect the key points in external testing dataset (396 images), the AP (average performance) for key point detection reach 86.4 %. Then we applied an additional post processing procedure to correct the output of HRNets so that the AP reaches 90.9 %. This result signifies that this system can effectively assist the evaluation of canine cardiomegaly in a real clinical scenario.

Fulltext Analysis on Entrepreneurship Psychology of Preschool Education Students With Entrepreneurial Intention

Yin Y, Yang L, Liu B

Front Psychol, 2020;11:1559.

PMID: 32733339 DOI: 10.3389/fpsyg.2020.01559

To diversify the creative thinking of preschool education students and improve their ability to innovate and start a business, a survey of preschool education students under entrepreneurial psychology theory was conducted in this research. Based on the theoretical foundation of entrepreneurial psychology, this article analyzed the entrepreneurial psychological quality and psychological education of college students. By investigating preschool education students in a certain college in Sichuan as the research object, the author explored the current entrepreneurial intentions of college students and their entrepreneurial psychological problems. In response to the current entrepreneurial situation of college graduates, relevant countermeasures were proposed from the perspective of the school to support their entrepreneurial psychology. Among the 205 preschool education college students, the students were more willing to give full play to their professional expertise in terms of employment intentions. At the same time, there were still situations in which students were dissatisfied with the prospects of preschool education career development and wanted to achieve the value of life through other approaches. Most students in preschool education had a wait-and-see attitude toward entrepreneurship. Only 35% of students had a clear intention to start a business and made their plans for entrepreneurship. More than 90% of students held that they had developed inadequate entrepreneurial ability, and 80% of students believed that they lacked the required professional knowledge. These two factors constitute the main reasons for students' negative attitudes toward entrepreneurship. Nevertheless, colleges may stimulate the potential of students' self-development through the improvement of entrepreneurial psychological education courses, the construction of psychological consultation institutions on campus, and the establishment of interactive platforms for entrepreneurship. In this way, students' entrepreneurial psychology can be cultivated in an all-round way. Therefore, to deal with the weak overall entrepreneurial consciousness of college students, the colleges should cultivate entrepreneurial innovative talents by strengthening the psychological education of entrepreneurship for students, and help college students achieve entrepreneurial success.

Efficacy and safety of weekly paclitaxel with or without ramucirumab as second-line therapy for the treatment of advanced gastric or gastroesophageal junction adenocarcinoma (RAINBOW-Asia): a randomised, multicentre, double-blind, phase 3 trial

Xu RH, Zhang Y, Pan H, Feng J, Zhang T, Liu T, et al.

Lancet Gastroenterol Hepatol, 2021 12;6(12):1015-1024.

PMID: 34626550 DOI: 10.1016/S2468-1253(21)00313-7

BACKGROUND: In the global phase 3 RAINBOW study, ramucirumab plus paclitaxel significantly improved overall survival compared with placebo plus paclitaxel in patients with advanced gastric or gastro-oesophageal junction (GEJ) adenocarcinoma. RAINBOW-Asia, a bridging study with similar design to RAINBOW, aimed to evaluate the efficacy and safety of ramucirumab plus paclitaxel for advanced gastric or GEJ adenocarcinoma in Asian, predominantly Chinese, patients.

METHODS: RAINBOW-Asia was a randomised, double-blind, placebo-controlled, phase 3 trial done at 32 centres in China, Malaysia, the Philippines, and Thailand. Adult patients (≥18 years) with metastatic or locally advanced, unresectable gastric or GEJ adenocarcinoma who previously received fluoropyrimidine-platinum-based chemotherapy were randomly assigned with a centralised interactive web response system in a 2:1 ratio to receive ramucirumab 8 mg/kg or placebo intravenously on days 1 and 15 plus paclitaxel 80 mg/m2 intravenously on days 1, 8, and 15 of every 28-day cycle. Randomisation was stratified by Eastern Cooperative Oncology Group performance status and presence of peritoneal metastases. The co-primary endpoints were progression-free survival and overall survival. Efficacy analyses were done in the intention-to-treat population, and safety analysis included patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, NCT02898077, and has been completed.

FINDINGS: Between March 2, 2017, and June 30, 2020, 440 patients were randomly assigned to receive ramucirumab plus paclitaxel (n=294) or placebo plus paclitaxel (n=146). Median progression-free survival was 4·14 months (95% CI 3·71-4·30) in the ramucirumab plus paclitaxel group compared with 3·15 months (2·83-4·14) in the placebo plus paclitaxel group (hazard ratio [HR] 0·765, 95% CI 0·613-0·955, p=0·0184). Median overall survival was 8·71 months (95% CI 7·98-9·49) in the ramucirumab plus paclitaxel group and 7·92 months (6·31-9·10) in the placebo plus paclitaxel group (HR 0·963, 95% CI 0·771-1·203, p=0·7426). The most common grade 3 or worse treatment-emergent adverse events were decreased neutrophil count (159 [54%] of 293 patients in the ramucirumab plus paclitaxel group vs 56 [39%] of 145 in the placebo plus paclitaxel group), decreased white blood cell count (127 [43%] vs 42 [29%]), anaemia (46 [16%] vs 24 [17%]), hypertension (21 [7%] vs nine [6%]), and febrile neutropenia (18 [6%] vs one [<1%]).

INTERPRETATION: These findings, along with the results from RAINBOW, support the use of ramucirumab plus paclitaxel as second-line therapy in a predominantly Chinese population with advanced gastric or GEJ adenocarcinoma.

FUNDING: Eli Lilly and Company, USA.

TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Fulltext Circulating purification of cutting fluid: an overview

Wu X, Li C, Zhou Z, Nie X, Chen Y, Zhang Y, et al.

Int J Adv Manuf Technol, 2021;117(9-10):2565-2600.

PMID: 34465936 DOI: 10.1007/s00170-021-07854-1

Cutting fluid has cooling and lubricating properties and is an important part of the field of metal machining. Owing to harmful additives, base oils with poor biodegradability, defects in processing methods, and unreasonable emissions of waste cutting fluids, cutting fluids have serious pollution problems, which pose challenges to global carbon emissions laws and regulations. However, the current research on cutting fluid and its circulating purification technique lacks systematic review papers to provide scientific technical guidance for actual production. In this study, the key scientific issues in the research achievements of eco-friendly cutting fluid and waste fluid treatment are clarified. First, the preparation and mechanism of organic additives are summarized, and the influence of the physical and chemical properties of vegetable base oils on lubricating properties is analyzed. Then, the process characteristics of cutting fluid reduction supply methods are systematically evaluated. Second, the treatment of oil mist and miscellaneous oil, the removal mechanism and approach of microorganisms, and the design principles of integrated recycling equipment are outlined. The conclusion is concluded that the synergistic effect of organic additives, biodegradable vegetable base oils and recycling purification effectively reduces the environmental pollution of cutting fluids. Finally, in view of the limitations of the cutting fluid and its circulating purification technique, the prospects of amino acid additive development, self-adapting jet parameter supply system, matching mechanism between processing conditions and cutting fluid are put forward, which provides the basis and support for the engineering application and development of cutting fluid and its circulating purification.

Fulltext A novel method for multifactorial bio-chemical experiments design based on combinational design theory

Wang X, Sun B, Liu B, Fu Y, Zheng P

PLoS One, 2017;12(11):e0186853.

PMID: 29095845 DOI: 10.1371/journal.pone.0186853

Experimental design focuses on describing or explaining the multifactorial interactions that are hypothesized to reflect the variation. The design introduces conditions that may directly affect the variation, where particular conditions are purposely selected for observation. Combinatorial design theory deals with the existence, construction and properties of systems of finite sets whose arrangements satisfy generalized concepts of balance and/or symmetry. In this work, borrowing the concept of "balance" in combinatorial design theory, a novel method for multifactorial bio-chemical experiments design is proposed, where balanced templates in combinational design are used to select the conditions for observation. Balanced experimental data that covers all the influencing factors of experiments can be obtianed for further processing, such as training set for machine learning models. Finally, a software based on the proposed method is developed for designing experiments with covering influencing factors a certain number of times.

Fulltext Kaempferia galanga L.: Progresses in Phytochemistry, Pharmacology, Toxicology and Ethnomedicinal Uses

Wang SY, Zhao H, Xu HT, Han XD, Wu YS, Xu FF, et al.

Front Pharmacol, 2021;12:675350.

PMID: 34737693 DOI: 10.3389/fphar.2021.675350

K. galanga is an aromatic medicinal herb. It is locally to India and distributed in China, Myanmar, Indonesia, Malaysia, and Thailand. K. galanga is a Traditional Chinese Herb Medicine (TCHM), which has been applied to treat cold, dry cough, toothaches, rheumatism, hypertension and so on. In addition, it has been used widely as spices since its highly aromas. The aim of this review is to compile and update the current progresses of ethnomedicinal uses, phytochemistry, pharmacology and toxicology of K. galanga. All the data on K. galanga were based on different classical literary works, multiple electronic databases including SciFinder, Web of Science, PubMed, etc. The results showed that ninety-seven compounds have been identified from rhizome of K. galanga, including terpenoids, phenolics, cyclic dipeptides, flavonoids, diarylheptanoids, fatty acids and esters. Modern pharmacology studies revealed that extracts or secondary metabolites of the herb possessed anti-inflammatory, anti-oxidant, anti-tumorous, anti-bacterial, and anti-angiogenesis effects, which were closely related to its abundant ethnomedicinal uses. In conclusion, although previous research works have provided various information of K. galanga, more in-depth studies are still necessary to systemically evaluate phytochemistry, pharmacological activities, toxicity and quality control of this herb.

Ethyl cinnamate suppresses tumor growth through anti-angiogenesis by attenuating VEGFR2 signal pathway in colorectal cancer

Wang S, Yang J, Kuang X, Li H, Du H, Wu Y, et al.

J Ethnopharmacol, 2024 May 23;326:117913.

PMID: 38360380 DOI: 10.1016/j.jep.2024.117913

ETHNOPHARMACOLOGICAL RELEVANCE: Kaempferia galanga Linn. is an aromatic medicinal herb with extensively applied in India, China, Malaysia and other South Asia countries for thousands of years. It has been mentioned to treat abdominal tumors. Ethyl cinnamate (EC), one of the main chemical constituents of the rhizome of K. galanga, exhibited nematocidal, sedative and vasorelaxant activities. However, its anti-angiogenic activity, and anti-tumor effect have not been investigated.

AIM OF THE STUDY: To investigate the anti-angiogenic mechanism of EC and its anti-tumor effect by suppressing angiogenesis.

MATERIALS AND METHODS: The in vitro anti-angiogenic effect was evaluated using HUVECs model induced by VEGF and zebrafish model in vivo. The influence of the EC on phosphorylation of VEGFR2 and its downstream signaling pathways were evaluated by western blotting assay. Molecule docking technology was conducted to explore the interaction between EC and VEGFR2. SPR assay was used for detecting the binding affinity between EC and VEGFR2. To further investigate the molecular mechanism of EC on anti-angiogenesis, VEGFR2 knockdown in HUVECs and examined the influence of the EC. Anti-tumor activity of EC was evaluated using colony formation assay and apoptosis assay. The inhibitory effect of EC on tumor growth was explored using HT29 colon cancer xenograft model.

RESULTS: EC obviously inhibited proliferation, migration, invasion and tube formation of VEGF-induced HUVECs. EC also induced apoptosis of HUVECs. Moreover, it inhibited the development of vessel formation in zebrafish. Further investigations demonstrated that EC could suppress the phosphorylation of VEGFR2, and its downstream signaling pathways were altered in VEGF-induced HUVECs. EC formed a hydrogen bond to bind with the ATP binding site of the VEGFR2, and EC-VEGFR2 interaction was shown in SPR assay. The suppressive effect of EC on angiogenesis was abrogated after VEGFR2 knockdown in HUVECs. EC inhibited the colon cancer cells colony formation and induced apoptosis. In addition, EC suppressed tumor growth in colon cancer xenograft model, and no detectable hepatotoxicity and nephrotoxicity. In addition, it inhibited the phosphorylation of VEGFR2, and its downstream signal pathways in tumor.

CONCLUSIONS: EC could inhibit tumor growth in colon cancer by suppressing angiogenesis via VEGFR2 signaling pathway, and suggested EC as a promising candidate for colon cancer treatment.

Fulltext Suppression of Excited ϒ States Relative to the Ground State in Pb-Pb Collisions at sqrt[s]_{NN}=5.02 TeV

Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, Brandstetter J, et al.

Phys Rev Lett, 2018 Apr 06;120(14):142301.

PMID: 29694144 DOI: 10.1103/PhysRevLett.120.142301

The relative yields of ϒ mesons produced in pp and Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV and reconstructed via the dimuon decay channel are measured using data collected by the CMS experiment. Double ratios are formed by comparing the yields of the excited states, ϒ(2S) and ϒ(3S), to the ground state, ϒ(1S), in both Pb-Pb and pp collisions at the same center-of-mass energy. The double ratios, [ϒ(nS)/ϒ(1S)]_{Pb-Pb}/[ϒ(nS)/ϒ(1S)]_{pp}, are measured to be 0.308±0.055(stat)±0.019(syst) for the ϒ(2S) and less than 0.26 at 95% confidence level for the ϒ(3S). No significant ϒ(3S) signal is found in the Pb-Pb data. The double ratios are studied as a function of collision centrality, as well as ϒ transverse momentum and rapidity. No significant dependencies are observed.

Search for the X(5568) State Decaying into B_{s}^{0}π^{±} in Proton-Proton Collisions at sqrt[s]=8 TeV

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.

Phys Rev Lett, 2018 May 18;120(20):202005.

PMID: 29864318 DOI: 10.1103/PhysRevLett.120.202005

A search for resonancelike structures in the B_{s}^{0}π^{±} invariant mass spectrum is performed using proton-proton collision data collected by the CMS experiment at the LHC at sqrt[s]=8 TeV, corresponding to an integrated luminosity of 19.7 fb^{-1}. The B_{s}^{0} mesons are reconstructed in the decay chain B_{s}^{0}→J/ψϕ, with J/ψ→μ^{+}μ^{-} and ϕ→K^{+}K^{-}. The B_{s}^{0}π^{±} invariant mass distribution shows no statistically significant peaks for different selection requirements on the reconstructed B_{s}^{0} and π^{±} candidates. Upper limits are set on the relative production rates of the X(5568) and B_{s}^{0} states times the branching fraction of the decay X(5568)^{±}→B_{s}^{0}π^{±}. In addition, upper limits are obtained as a function of the mass and the natural width of possible exotic states decaying into B_{s}^{0}π^{±}.

Measurement of Prompt D^{0} Meson Azimuthal Anisotropy in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.

Phys Rev Lett, 2018 May 18;120(20):202301.

PMID: 29864330 DOI: 10.1103/PhysRevLett.120.202301

The prompt D^{0} meson azimuthal anisotropy coefficients, v_{2} and v_{3}, are measured at midrapidity (|y|<1.0) in Pb-Pb collisions at a center-of-mass energy sqrt[s_{NN}]=5.02 TeV per nucleon pair with data collected by the CMS experiment. The measurement is performed in the transverse momentum (p_{T}) range of 1 to 40 GeV/c, for central and midcentral collisions. The v_{2} coefficient is found to be positive throughout the p_{T} range studied. The first measurement of the prompt D^{0} meson v_{3} coefficient is performed, and values up to 0.07 are observed for p_{T} around 4 GeV/c. Compared to measurements of charged particles, a similar p_{T} dependence, but smaller magnitude for p_{T}<6 GeV/c, is found for prompt D^{0} meson v_{2} and v_{3} coefficients. The results are consistent with the presence of collective motion of charm quarks at low p_{T} and a path length dependence of charm quark energy loss at high p_{T}, thereby providing new constraints on the theoretical description of the interactions between charm quarks and the quark-gluon plasma.

Observation of Medium-Induced Modifications of Jet Fragmentation in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV Using Isolated Photon-Tagged Jets

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.

Phys Rev Lett, 2018 Dec 14;121(24):242301.

PMID: 30608764 DOI: 10.1103/PhysRevLett.121.242301

Measurements of fragmentation functions for jets associated with an isolated photon are presented for the first time in pp and Pb-Pb collisions. The analysis uses data collected with the CMS detector at the CERN LHC at a nucleon-nucleon center-of-mass energy of 5.02 TeV. Fragmentation functions are obtained for jets with p_{T}^{jet}>30 GeV/c in events containing an isolated photon with p_{T}^{γ}>60 GeV/c, using charged tracks with transverse momentum p_{T}^{trk}>1 GeV/c in a cone around the jet axis. The association with an isolated photon constrains the initial p_{T} and azimuthal angle of the parton whose shower produced the jet. For central Pb-Pb collisions, modifications of the jet fragmentation functions are observed when compared to those measured in pp collisions, while no significant differences are found in the 50% most peripheral collisions. Jets in central Pb-Pb events show an excess (depletion) of low (high) p_{T} particles, with a transition around 3 GeV/c. This measurement shows for the first time the in-medium shower modifications of partons (quark dominated) with well-defined initial kinematics. It constitutes a new well-controlled reference for testing theoretical models of the parton passage through the quark-gluon plasma.

Fulltext Relative Modification of Prompt ψ(2S) and J/ψ Yields from pp to PbPb Collisions at sqrt[s_{NN}]=5.02 TeV

Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, Brandstetter J, et al.

Phys Rev Lett, 2017 Apr 21;118(16):162301.

PMID: 28474955 DOI: 10.1103/PhysRevLett.118.162301

The relative modification of the prompt ψ(2S) and J/ψ yields from pp to PbPb collisions, at the center-of-mass energy of 5.02 TeV per nucleon pair, is presented. The analysis is based on pp and PbPb data samples collected by the CMS experiment at the LHC in 2015, corresponding to integrated luminosities of 28.0 pb^{-1} and 464 μb^{-1}, respectively. The double ratio of measured yields of prompt charmonia reconstructed through their decays into muon pairs, (N_{ψ(2S)}/N_{J/ψ})_{PbPb}/(N_{ψ(2S)}/N_{J/ψ})_{pp}, is determined as a function of PbPb collision centrality and charmonium transverse momentum p_{T}, in two kinematic intervals: |y|<1.6 covering 6.5

Measurement of the Splitting Function in pp and Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.

Phys Rev Lett, 2018 Apr 06;120(14):142302.

PMID: 29694107 DOI: 10.1103/PhysRevLett.120.142302

Data from heavy ion collisions suggest that the evolution of a parton shower is modified by interactions with the color charges in the dense partonic medium created in these collisions, but it is not known where in the shower evolution the modifications occur. The momentum ratio of the two leading partons, resolved as subjets, provides information about the parton shower evolution. This substructure observable, known as the splitting function, reflects the process of a parton splitting into two other partons and has been measured for jets with transverse momentum between 140 and 500 GeV, in pp and PbPb collisions at a center-of-mass energy of 5.02 TeV per nucleon pair. In central PbPb collisions, the splitting function indicates a more unbalanced momentum ratio, compared to peripheral PbPb and pp collisions.. The measurements are compared to various predictions from event generators and analytical calculations.

Fulltext Search for dark matter produced in association with heavy-flavor quark pairs in proton-proton collisions at s = 13 TeV

Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, Brandstetter J, et al.

Eur Phys J C Part Fields, 2017;77(12):845.

PMID: 31985736 DOI: 10.1140/epjc/s10052-017-5317-4

A search is presented for an excess of events with heavy-flavor quark pairs (

t

t
¯

and

b

b
¯

) and a large imbalance in transverse momentum in data from proton-proton collisions at a center-of-mass energy of 13

TeV

. The data correspond to an integrated luminosity of 2.2

fb

-
1

collected with the CMS detector at the CERN LHC. No deviations are observed with respect to standard model predictions. The results are used in the first interpretation of dark matter production in

t

t
¯

and

b

b
¯

final states in a simplified model. This analysis is also the first to perform a statistical combination of searches for dark matter produced with different heavy-flavor final states. The combination provides exclusions that are stronger than those achieved with individual heavy-flavor final states.

Fulltext Search for standard model production of four top quarks with same-sign and multilepton final states in proton-proton collisions at s = 13 TeV

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2018;78(2):140.

PMID: 31265001 DOI: 10.1140/epjc/s10052-018-5607-5

A search for standard model production of four top quarks ( t t ¯ t t ¯ ) is reported using events containing at least three leptons ( e , μ ) or a same-sign lepton pair. The events are produced in proton-proton collisions at a center-of-mass energy of 13 TeV at the LHC, and the data sample, recorded in 2016, corresponds to an integrated luminosity of 35.9 fb - 1 . Jet multiplicity and flavor are used to enhance signal sensitivity, and dedicated control regions are used to constrain the dominant backgrounds. The observed and expected signal significances are, respectively, 1.6 and 1.0 standard deviations, and the t t ¯ t t ¯ cross section is measured to be 16 . 9 - 11.4 + 13.8 fb , in agreement with next-to-leading-order standard model predictions. These results are also used to constrain the Yukawa coupling between the top quark and the Higgs boson to be less than 2.1 times its expected standard model value at 95% confidence level.

Fulltext Search for new physics in events with a leptonically decaying Z boson and a large transverse momentum imbalance in proton-proton collisions at s = 13 TeV

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2018;78(4):291.

PMID: 31007582 DOI: 10.1140/epjc/s10052-018-5740-1

A search for new physics in events with a Z boson produced in association with large missing transverse momentum at the LHC is presented. The search is based on the 2016 data sample of proton-proton collisions recorded with the CMS experiment at s = 13 TeV , corresponding to an integrated luminosity of 35.9 fb - 1 . The results of this search are interpreted in terms of a simplified model of dark matter production via spin-0 or spin-1 mediators, a scenario with a standard-model-like Higgs boson produced in association with the Z boson and decaying invisibly, a model of unparticle production, and a model with large extra spatial dimensions. No significant deviations from the background expectations are found, and limits are set on relevant model parameters, significantly extending the results previously achieved in this channel.

Fulltext Study of dijet events with a large rapidity gap between the two leading jets in pp collisions at s = 7 TeV

Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, Brandstetter J, et al.

Eur Phys J C Part Fields, 2018;78(3):242.

PMID: 31264999 DOI: 10.1140/epjc/s10052-018-5691-6

Events with no charged particles produced between the two leading jets are studied in proton-proton collisions at s = 7 TeV . The jets were required to have transverse momentum p T jet > 40 GeV and pseudorapidity 1.5 < | η jet | < 4.7 , and to have values of η jet with opposite signs. The data used for this study were collected with the CMS detector during low-luminosity running at the LHC, and correspond to an integrated luminosity of 8 pb - 1 . Events with no charged particles with p T > 0.2 GeV in the interval - 1 < η < 1 between the jets are observed in excess of calculations that assume no color-singlet exchange. The fraction of events with such a rapidity gap, amounting to 0.5-1% of the selected dijet sample, is measured as a function of the p T of the second-leading jet and of the rapidity separation between the jets. The data are compared to previous measurements at the Tevatron, and to perturbative quantum chromodynamics calculations based on the Balitsky-Fadin-Kuraev-Lipatov evolution equations, including different models of the non-perturbative gap survival probability.

Fulltext Measurement of the triple-differential dijet cross section in proton-proton collisions at s = 8 TeV and constraints on parton distribution functions

Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, Brandstetter J, et al.

Eur Phys J C Part Fields, 2017;77(11):746.

PMID: 31999281 DOI: 10.1140/epjc/s10052-017-5286-7

A measurement is presented of the triple-differential dijet cross section at a centre-of-mass energy of 8 TeV using 19.7 fb -1 of data collected with the CMS detector in proton-proton collisions at the LHC. The cross section is measured as a function of the average transverse momentum, half the rapidity separation, and the boost of the two leading jets in the event. The cross section is corrected for detector effects and compared to calculations in perturbative quantum chromodynamics at next-to-leading order accuracy, complemented with electroweak and nonperturbative corrections. New constraints on parton distribution functions are obtained and the inferred value of the strong coupling constant is α S ( M Z ) = 0.1199 ± 0.0015 ( exp ) - 0.0020 + 0.0031 ( theo ) , where M Z is the mass of the Z boson.

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