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Membrane inflammasome activation by choriodecidual Ureaplasma parvum infection without intra-amniotic infection in a Non-Human Primate model†. Biol Reprod 2024; 110:971-984. [PMID: 38335245 PMCID: PMC11094395 DOI: 10.1093/biolre/ioae027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/29/2023] [Accepted: 02/02/2024] [Indexed: 02/12/2024] Open
Abstract
Intrauterine infection is a significant cause of neonatal morbidity and mortality. Ureaplasma parvum is a microorganism commonly isolated from cases of preterm birth and preterm premature rupture of membranes (pPROM). However, the mechanisms of early stage ascending reproductive tract infection remain poorly understood. To examine inflammation in fetal (chorioamnionic) membranes we utilized a non-human primate (NHP) model of choriodecidual U. parvum infection. Eight chronically catheterized pregnant rhesus macaques underwent maternal-fetal catheterization surgery at ~105-112 days gestation and choriodecidual inoculation with U. parvum (105 CFU/mL, n =4) or sterile media (controls; n = 4) starting at 115-119 days, repeated at 5-day intervals until C-section at 136-140 days (term=167 days). The average inoculation to delivery interval was 21 days, and Ureaplasma infection of the amniotic fluid (AF) was undetectable in all animals. Choriodecidual Ureaplasma infection resulted in increased fetal membrane expression of MMP-9 and PTGS2, but did not result in preterm labor or increased concentrations of AF pro-inflammatory cytokines. However, membrane expression of inflammasome sensors, NLRP3, NLRC4, AIM2, and NOD2, and adaptor ASC (PYCARD) gene expression were significantly increased. Gene expression of IL-1β, IL-18, IL-18R1 , CASPASE-1, and pro-CASPASE-1 protein increased with Ureaplasma infection. Downstream inflammatory genes MYD88 and NFκB (Nuclear factor kappa-light-chain-enhancer of activated B cells) were also significantly upregulated. These results demonstrate that choriodecidual Ureaplasma infection, can cause activation of inflammasome complexes and pathways associated with pPROM and preterm labor prior to microbes being detectable in the AF.
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Emergence of Long-Range Angular Correlations in Low-Multiplicity Proton-Proton Collisions. PHYSICAL REVIEW LETTERS 2024; 132:172302. [PMID: 38728735 DOI: 10.1103/physrevlett.132.172302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 02/22/2024] [Accepted: 03/22/2024] [Indexed: 05/12/2024]
Abstract
This Letter presents the measurement of near-side associated per-trigger yields, denoted ridge yields, from the analysis of angular correlations of charged hadrons in proton-proton collisions at sqrt[s]=13 TeV. Long-range ridge yields are extracted for pairs of charged particles with a pseudorapidity difference of 1.4<|Δη|<1.8 and a transverse momentum of 1
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First Measurement of the |t| Dependence of Incoherent J/ψ Photonuclear Production. PHYSICAL REVIEW LETTERS 2024; 132:162302. [PMID: 38701458 DOI: 10.1103/physrevlett.132.162302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 11/22/2023] [Accepted: 01/23/2024] [Indexed: 05/05/2024]
Abstract
The first measurement of the cross section for incoherent photonuclear production of J/ψ vector mesons as a function of the Mandelstam |t| variable is presented. The measurement was carried out with the ALICE detector at midrapidity, |y|<0.8, using ultraperipheral collisions of Pb nuclei at a center-of-mass energy per nucleon pair of sqrt[s_{NN}]=5.02 TeV. This rapidity interval corresponds to a Bjorken-x range (0.3-1.4)×10^{-3}. Cross sections are given in five |t| intervals in the range 0.04<|t|<1 GeV^{2} and compared to the predictions by different models. Models that ignore quantum fluctuations of the gluon density in the colliding hadron predict a |t| dependence of the cross section much steeper than in data. The inclusion of such fluctuations in the same models provides a better description of the data.
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Relaxin Modulates the Genomic Actions and Biological Effects of Estrogen in the Myometrium by Reducing Estrogen Receptor Alpha Phosphorylation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.15.589654. [PMID: 38659934 PMCID: PMC11042280 DOI: 10.1101/2024.04.15.589654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Estradiol (E2) and relaxin (Rln) are steroid and polypeptide hormones, respectively, with important roles in the female reproductive tract, including myometrium. Some actions of Rln, which are mediated by its membrane receptor RXFP1, require or are augmented by E2 signaling through its cognate nuclear steroid receptor, estrogen receptor alpha (ERα). In contrast, other actions of Rln act in opposition to the effects of E2. Here we explore the molecular and genomic mechanisms that underlie the functional interplay between E2 and Rln in the myometrium. We used both ovariectomized female mice and immortalized human myometrial cells expressing wild type or mutant ERα (hTERT-HM-ERα cells). Our results indicate that Rln attenuates the genomic actions and biological effects of estrogen in the myometrium and myometrial cells by reducing phosphorylation ERα on serine 118 (S118). Interestingly, we observed a potent inhibitory effect of Rln on the E2-dependent binding of ERα across the genome. The reduction in ERα binding was associated with changes in the hormone-regulated transcriptome, including a decrease in the E2-dependent expression of neighboring genes. The inhibitory effects of Rln cotreatment on the E2-dependent phosphorylation of ERα required the nuclear dual-specificity phosphatases DUSP1 and DUSP5. Moreover, the inhibitory effects of Rln were reflected in a concomitant inhibition of the E2-dependent contraction of myometrial cells. Collectively, our results identify a pathway that integrates Rln/RXFP1 and E2/ERα signaling, resulting in a convergence of membrane and nuclear signaling pathways to control genomic and biological outcomes.
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ψ(2S) Suppression in Pb-Pb Collisions at the LHC. PHYSICAL REVIEW LETTERS 2024; 132:042301. [PMID: 38335364 DOI: 10.1103/physrevlett.132.042301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 05/25/2023] [Accepted: 11/20/2023] [Indexed: 02/12/2024]
Abstract
The production of the ψ(2S) charmonium state was measured with ALICE in Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV, in the dimuon decay channel. A significant signal was observed for the first time at LHC energies down to zero transverse momentum, at forward rapidity (2.5
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Facial nerve communication with ansa cervicalis - An unusual anatomical variation. J Postgrad Med 2024; 70:60-63. [PMID: 38037772 PMCID: PMC10947731 DOI: 10.4103/jpgm.jpgm_454_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 08/03/2023] [Accepted: 08/14/2023] [Indexed: 12/02/2023] Open
Abstract
Neural connections of the seventh cranial nerve with its neighboring nerves are common and well documented; however, communication with ansa cervicalis is as yet unknown. We present a case with such a connection found during cadaveric dissection, with hitherto unknown consequences. In this specimen, after giving the marginal mandibular and cervical branches, the cervicofacial division continued distally to communicate with the distal loop of ansa cervicalis. Presence of such connection may result in facial muscle paralysis on injury to the ansa or strap muscle paralysis on injury to the facial nerve, depending on the direction of nerve fibers. Such unusual connections bring to light the need for extreme care during surgeries in the neck to safeguard any such connections and when using the ansa as donor.
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Long-term follow-up of persons diagnosed with multidrug-resistant TB in Chennai, India, 2013-2020. Int J Tuberc Lung Dis 2024; 28:54-56. [PMID: 38178300 PMCID: PMC10859871 DOI: 10.5588/ijtld.23.0272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024] Open
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Excited state spectroscopy and spin splitting in single layer MoS 2 quantum dots. NANOSCALE 2023; 15:18203-18211. [PMID: 37920920 DOI: 10.1039/d3nr03844k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2023]
Abstract
Semiconducting transition metal dichalcogenides (TMDCs) are very promising materials for quantum dots and spin-qubit implementation. Reliable operation of spin qubits requires the knowledge of the Landé g-factor, which can be measured by exploiting the discrete energy spectrum on a quantum dot. However, the quantum dots realized in TMDCs are yet to reach the required control and quality for reliable measurement of excited state spectroscopy and the g-factor, particularly in atomically thin layers. Quantum dot sizes reported in TMDCs so far are not small enough to observe discrete energy levels on them. Here, we report on electron transport through discrete energy levels of quantum dots in a single layer MoS2 isolated from its environment using a dual gate geometry. The quantum dot energy levels are separated by a few (5-6) meV such that the ground state and the first excited state transitions are clearly visible, thanks to the low contact resistance of ∼700 Ω and relatively low gate voltages. This well-resolved energy separation allowed us to accurately measure the ground state g-factor of ∼5 in MoS2 quantum dots. We observed a spin-filling sequence in our quantum dots under a perpendicular magnetic field. Such a system offers an excellent testbed to measure the key parameters for evaluation and implementation of spin-valley qubits in TMDCs, thus accelerating the development of quantum systems in two-dimensional semiconducting TMDCs.
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Measurements of Groomed-Jet Substructure of Charm Jets Tagged by D^{0} Mesons in Proton-Proton Collisions at sqrt[s]=13 TeV. PHYSICAL REVIEW LETTERS 2023; 131:192301. [PMID: 38000395 DOI: 10.1103/physrevlett.131.192301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 01/13/2023] [Accepted: 07/19/2023] [Indexed: 11/26/2023]
Abstract
Understanding the role of parton mass and Casimir color factors in the quantum chromodynamics parton shower represents an important step in characterizing the emission properties of heavy quarks. Recent experimental advances in jet substructure techniques have provided the opportunity to isolate and characterize gluon emissions from heavy quarks. In this Letter, the first direct experimental constraint on the charm-quark splitting function is presented, obtained via the measurement of the groomed shared momentum fraction of the first splitting in charm jets, tagged by a reconstructed D^{0} meson. The measurement is made in proton-proton collisions at sqrt[s]=13 TeV, in the low jet transverse-momentum interval of 15≤p_{T}^{jet ch}<30 GeV/c where the emission properties are sensitive to parton mass effects. In addition, the opening angle of the first perturbative emission of the charm quark, as well as the number of perturbative emissions it undergoes, is reported. Comparisons to measurements of an inclusive-jet sample show a steeper splitting function for charm quarks compared with gluons and light quarks. Charm quarks also undergo fewer perturbative emissions in the parton shower, with a reduced probability of large-angle emissions.
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Membrane Inflammasome Activation by Choriodecidual Ureaplasma parvum Infection without Intra-Amniotic Infection in an NHP Model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.18.557989. [PMID: 37781578 PMCID: PMC10541100 DOI: 10.1101/2023.09.18.557989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Intrauterine infection is a significant cause of preterm labor and neonatal morbidity and mortality. Ureaplasma parvum is the micro-organism most commonly isolated from cases of preterm birth and preterm premature rupture of membranes (pPROM). However, the mechanisms during the early stages of ascending reproductive tract infection that initiate maternal-fetal inflammatory pathways, preterm birth and pPROM remain poorly understood. To examine inflammation in fetal (chorioamnionic) membranes in response to Ureaplasma parvum infection, we utilized a novel in vivo non-human primate model of early choriodecidual infection. Eight chronically catheterized pregnant rhesus macaques underwent maternal-fetal catheterization surgery at 105-112 days gestation and choriodecidual inoculation with Ureaplasma parvum (10 5 cfu/mL of a low passaged clinical isolate, serovar 1; n=4) or saline/sterile media (Controls; n=4) starting at 115-119 days gestation, repeated every 5 days until scheduled cesarean-section at 136-140d gestation (term=167d). The average inoculation to delivery interval was 21 days and Ureaplasma infection of the amniotic fluid was undetectable by culture and PCR in all animals. Inflammatory mediators in amniotic fluid (AF) were assessed by Luminex, ELISA and multiplex assays. RNA was extracted from the chorion and amnionic membranes for single gene analysis (qRT-PCR) and protein expression was determined by Western blot and immunohistochemistry. Our NHP model of choriodecidual Ureaplasma infection, representing an early-stage ascending reproductive tract infection without microbial invasion of the amniotic cavity, resulted in increased fetal membrane protein and gene expression of MMP-9 and PTGS2, but did not result in preterm labor (no increase in uterine contractility) or increased concentrations of amniotic fluid pro-inflammatory cytokines (IL-1β, IL-6, IL-8, IL-18, TNF-α). However, membrane expression of inflammasome sensor molecules, NLRP3, NLRC4, AIM2 and NOD2, and the adaptor protein ASC ( PYCARD ) gene expression were significantly increased in the Ureaplasma group when compared to non-infected controls. Gene expression of IL-1 β, IL-18, the IL-18R1 receptor , CASPASE-1 and pro-CASPASE-1 protein were also increased in the fetal membranes with Ureaplasma infection. Downstream inflammatory signaling genes MYD88 was also significantly upregulated in both the amnion and chorion, along with a significant increase in NFKB in the chorion. These results demonstrate that even at the early stages of ascending reproductive tract Ureaplasma infection, activation of inflammasome complexes and pathways associated with degradation of chorioamnionic membrane integrity are present. This study therefore provides experimental evidence for the importance of the early stages of ascending Ureaplasma infection in initiating processes of pPROM and preterm labor. These findings have implications for the identification of intrauterine inflammation before microbes are detectable in the amniotic fluid (sterile inflammation) and the timing of potential treatments for preterm labor and fetal injury caused by intrauterine infection.
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Measurement of the Lifetime and Λ Separation Energy of _{Λ}^{3}H. PHYSICAL REVIEW LETTERS 2023; 131:102302. [PMID: 37739380 DOI: 10.1103/physrevlett.131.102302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 01/18/2023] [Accepted: 07/21/2023] [Indexed: 09/24/2023]
Abstract
The most precise measurements to date of the _{Λ}^{3}H lifetime τ and Λ separation energy B_{Λ} are obtained using the data sample of Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV collected by ALICE at the LHC. The _{Λ}^{3}H is reconstructed via its charged two-body mesonic decay channel (_{Λ}^{3}H→^{3}He+π^{-} and the charge-conjugate process). The measured values τ=[253±11(stat)±6(syst)] ps and B_{Λ}=[102±63(stat)±67(syst)] keV are compatible with predictions from effective field theories and confirm that the _{Λ}^{3}H structure is consistent with a weakly bound system.
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Measurement of the J/ψ Polarization with Respect to the Event Plane in Pb-Pb Collisions at the LHC. PHYSICAL REVIEW LETTERS 2023; 131:042303. [PMID: 37566833 DOI: 10.1103/physrevlett.131.042303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 02/09/2023] [Accepted: 03/28/2023] [Indexed: 08/13/2023]
Abstract
We study the polarization of inclusive J/ψ produced in Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV at the LHC in the dimuon channel, via the measurement of the angular distribution of its decay products. We perform the study in the rapidity region 2.5
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First Measurement of Antideuteron Number Fluctuations at Energies Available at the Large Hadron Collider. PHYSICAL REVIEW LETTERS 2023; 131:041901. [PMID: 37566856 DOI: 10.1103/physrevlett.131.041901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 07/01/2022] [Accepted: 09/15/2022] [Indexed: 08/13/2023]
Abstract
The first measurement of event-by-event antideuteron number fluctuations in high energy heavy-ion collisions is presented. The measurements are carried out at midrapidity (|η|<0.8) as a function of collision centrality in Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV using the ALICE detector. A significant negative correlation between the produced antiprotons and antideuterons is observed in all collision centralities. The results are compared with a state-of-the-art coalescence calculation. While it describes the ratio of higher order cumulants of the antideuteron multiplicity distribution, it fails to describe quantitatively the magnitude of the correlation between antiproton and antideuteron production. On the other hand, thermal-statistical model calculations describe all the measured observables within uncertainties only for correlation volumes that are different with respect to those describing proton yields and a similar measurement of net-proton number fluctuations.
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Enhanced Deuteron Coalescence Probability in Jets. PHYSICAL REVIEW LETTERS 2023; 131:042301. [PMID: 37566840 DOI: 10.1103/physrevlett.131.042301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 04/07/2023] [Accepted: 06/05/2023] [Indexed: 08/13/2023]
Abstract
The transverse-momentum (p_{T}) spectra and coalescence parameters B_{2} of (anti)deuterons are measured in p-p collisions at sqrt[s]=13 TeV for the first time in and out of jets. In this measurement, the direction of the leading particle with the highest p_{T} in the event (p_{T}^{lead}>5 GeV/c) is used as an approximation for the jet axis. The event is consequently divided into three azimuthal regions, and the jet signal is obtained as the difference between the toward region, that contains jet fragmentation products in addition to the underlying event (UE), and the transverse region, which is dominated by the UE. The coalescence parameter in the jet is found to be approximately a factor of 10 larger than that in the underlying event. This experimental observation is consistent with the coalescence picture and can be attributed to the smaller average phase-space distance between nucleons in the jet cone as compared with the underlying event. The results presented in this Letter are compared to predictions from a simple nucleon coalescence model, where the phase-space distributions of nucleons are generated using pythia8 with the Monash 2013 tuning, and to predictions from a deuteron production model based on ordinary nuclear reactions with parametrized energy-dependent cross sections tuned on data. The latter model is implemented in pythia8.3. Both models reproduce the observed large difference between in-jet and out-of-jet coalescence parameters, although the almost flat trend of the B_{2}^{Jet} is not reproduced by the models, which instead give a decreasing trend.
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Detection of Human Papillomavirus among Cervical Cancer Patients by Qualitative Polymerase Chain Reaction on Formalin- fixed, Paraffin-embedded Tissue: A Retrospective Observational Analysis. NATIONAL JOURNAL OF LABORATORY MEDICINE 2023. [DOI: 10.7860/njlm/2023/58623.2705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Introduction: Cervical cancer is second most commonly diagnosed and third most common cause for cancer death among women in the developing countries. It is now-established that Human Papillomavirus (HPV) infection is responsible for pathogenesis of cervical cancer. HPV Deoxyribonucleic Acid (DNA) detection is generally done on cytology specimens to triage women undergoing cervical cancer screening, but testing of Formalin-fixed, Paraffin- embedded tissue (FFPE) is not yet widely used. Aim: To study the detection of HPV by Qualitative PCR by extraction of DNA from FFPE. Materials and Methods: This retrospective observational analysis was carried out at Department of Pathology, Armed Forces Medical College, Pune, Maharashtra, India, managed at the centre from 2008 to 2015. The data analysis was done Aug 2013-Oct 2015 on 35 patients of cervical cancer which were reconfirmed by histopatholgical study of sections. Tissue blocks were obtained from the selected subjects and 3-5 micron sections were taken and prepared for Haematoxylin and Eosin (H&E) staining. Qualitative PCR was run on DNA extracted from FFPE tissue for evaluation of HPV. The amplified DNA varied between 230-270 base pairs (bp) and was analysed for oncogenic HPV type 16, 18, 31, 33, 35, 45, 52b and 58 by gel electrophoresis. Data was tabulated in Microsoft excel and mean, frequency and percentages were calculated. Pearson’s Chi-square test was used to calculate the significance. Results: Out of the total 35 samples analysed (mean age: 51.08±10.6 years),15 cases were large cell non keratinising carcinoma, 12 cases of keratinising squamous cell carcinoma, 5 cases of carcinoma in-situ and 3 cases were adenocarcinoma. A total of 13 cases out of 35 showed the bands of HPV genomes, indicating either of the HPV strain. Conclusion: Although molecular diagnostics on FFPE tissue is need of hour, stringent protocols for timing of fixation, technical expertise for extraction of DNA or Ribonucleic Acid (RNA), careful handling of the sample and quality control is of paramount importance. Fragmentation is a problem in DNA extracted from FFPE tissue, so primers having small base pairs should be used to maximise the yield.
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Purple urinary bag syndrome: Our experience. Med J Armed Forces India 2023; 79:21-25. [PMID: 36605349 PMCID: PMC9807677 DOI: 10.1016/j.mjafi.2020.08.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 08/28/2020] [Indexed: 01/09/2023] Open
Abstract
Background Purple urinary bag syndrome (PUBS) is a visually striking and rare manifestation of urinary tract infection characterised by purple discolouration of the catheter and the urobag, which are seen primarily in patients who are on long-term indwelling catheter. This rare syndrome results due to the breakdown of indole, a by-product of dietary tryptophan metabolism, to coloured pigments indigo and indirubin by urinary bacteria, which reacts with the catheter and the bag to impart a purple colour. Methods This was a prospective observational study, wherein all cases of PUBS diagnosed between March 2012 and February 2020 were analysed and followed up. Results A total of five patients were presented with PUBS. Among them, four were women, and four were chronically constipated. All of them were elderly and debilitated with either being bed bound or having restricted mobility. Three of them had associated chronic kidney disease. All of them were treated successfully with change of catheters and antibiotics. Conclusion This rare but alarming condition occurs in elderly patients who are on long-term indwelling catheters. The diagnosis is visually apparent, and the treatment may be just a simple change of catheter with oral antibiotics. The awareness may help in correct diagnosis and treatment.
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Progesterone and its receptor signaling in cervical remodeling: Mechanisms of physiological actions and therapeutic implications. J Steroid Biochem Mol Biol 2022; 223:106137. [PMID: 35690241 PMCID: PMC9509468 DOI: 10.1016/j.jsbmb.2022.106137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 05/26/2022] [Accepted: 06/06/2022] [Indexed: 10/18/2022]
Abstract
The remodeling of the cervix from a closed rigid structure to one that can open sufficiently for passage of a term infant is achieved by a complex series of molecular events that in large part are regulated by the steroid hormones progesterone and estrogen. Among hormonal influences, progesterone exerts a dominant role for most of pregnancy to initiate a loss of tissue strength yet maintain competence in a phase termed softening. Equally important are the molecular events that abrogate progesterone function in late pregnancy to allow a loss of tissue competence and strength during cervical ripening and dilation. In this review, we focus on current understanding by which progesterone receptor signaling for the majority of pregnancy followed by a loss/shift in progesterone receptor action at the end of pregnancy, collectively ensure cervical remodeling as necessary for successful parturition.
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First study of the two-body scattering involving charm hadrons. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.106.052010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Hypertriton Production in p-Pb Collisions at sqrt[s_{NN}]=5.02 TeV. PHYSICAL REVIEW LETTERS 2022; 128:252003. [PMID: 35802430 DOI: 10.1103/physrevlett.128.252003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 01/28/2022] [Accepted: 06/03/2022] [Indexed: 06/15/2023]
Abstract
The study of nuclei and antinuclei production has proven to be a powerful tool to investigate the formation mechanism of loosely bound states in high-energy hadronic collisions. The first measurement of the production of _{Λ}^{3}H in p-Pb collisions at sqrt[s_{NN}]=5.02 TeV is presented in this Letter. Its production yield measured in the rapidity interval -1<y<0 for the 40% highest-multiplicity p-Pb collisions is dN/dy=[6.3±1.8(stat)±1.2(syst)]×10^{-7}. The measurement is compared with the expectations of statistical hadronization and coalescence models, which describe the nucleosynthesis in hadronic collisions. These two models predict very different yields of the hypertriton in charged particle multiplicity environments relevant to small collision systems such as p-Pb, and therefore the measurement of dN/dy is crucial to distinguish between them. The precision of this measurement leads to the exclusion with a significance larger than 6.9σ of some configurations of the statistical hadronization model, thus constraining the theory behind the production of loosely bound states at hadron colliders.
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In vitro study on efficacy of PHELA, an African traditional drug against SARS-CoV-2. Sci Rep 2022; 12:10305. [PMID: 35718800 PMCID: PMC9207029 DOI: 10.1038/s41598-022-13599-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 05/09/2022] [Indexed: 11/26/2022] Open
Abstract
In 2019, coronavirus has made the third apparition in the form of SARS-CoV-2, a novel strain of coronavirus that is extremely pathogenic and it uses the same receptor as SARS-CoV, the angiotensin-converting enzyme 2 (ACE2). However, more than 182 vaccine candidates have been announced; and 12 vaccines have been approved for use, although, even vaccinated individuals are still vulnerable to infection. In this study, we investigated PHELA, recognized as an herbal combination of four exotic African medicinal plants namely; Clerodendrum glabrum E. Mey. Lamiaceae, Gladiolus dalenii van Geel, Rotheca myricoides (Hochst.) Steane & Mabb, and Senna occidentalis (L.) Link; as a candidate therapy for COVID-19. In vitro testing found that PHELA inhibited > 90% of SARS-CoV-2 and SARS-CoV infection at concentration levels of 0.005 mg/ml to 0.03 mg/ml and close to 100% of MERS-CoV infection at 0.1 mg/ml to 0.6 mg/ml. The in vitro average IC50 of PHELA on SARS-COV-2, SARS-CoV and MERS-COV were ~ 0.01 mg/ml. Secondly in silico docking studies of compounds identified in PHELA showed very strong binding energy interactions with the SARS-COV-2 proteins. Compound 5 showed the highest affinity for SARS-COV-2 protein compared to other compounds with the binding energy of − 6.8 kcal mol−1. Our data showed that PHELA has potential and could be developed as a COVID-19 therapeutic.
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Polarization of Λ and Λ[over ¯] Hyperons along the Beam Direction in Pb-Pb Collisions at sqrt[s]_{NN}=5.02 TeV. PHYSICAL REVIEW LETTERS 2022; 128:172005. [PMID: 35570422 DOI: 10.1103/physrevlett.128.172005] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 01/04/2022] [Accepted: 03/16/2022] [Indexed: 06/15/2023]
Abstract
The polarization of the Λ and Λ[over ¯] hyperons along the beam (z) direction, P_{z}, has been measured in Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV recorded with ALICE at the Large Hadron Collider (LHC). The main contribution to P_{z} comes from elliptic flow-induced vorticity and can be characterized by the second Fourier sine coefficient P_{z,s2}=⟨P_{z}sin(2φ-2Ψ_{2})⟩, where φ is the hyperon azimuthal emission angle and Ψ_{2} is the elliptic flow plane angle. We report the measurement of P_{z,s2} for different collision centralities and in the 30%-50% centrality interval as a function of the hyperon transverse momentum and rapidity. The P_{z,s2} is positive similarly as measured by the STAR Collaboration in Au-Au collisions at sqrt[s_{NN}]=200 GeV, with somewhat smaller amplitude in the semicentral collisions. This is the first experimental evidence of a nonzero hyperon P_{z} in Pb-Pb collisions at the LHC. The comparison of the measured P_{z,s2} with the hydrodynamic model calculations shows sensitivity to the competing contributions from thermal and the recently found shear-induced vorticity, as well as to whether the polarization is acquired at the quark-gluon plasma or the hadronic phase.
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Measurement of the Groomed Jet Radius and Momentum Splitting Fraction in pp and Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV. PHYSICAL REVIEW LETTERS 2022; 128:102001. [PMID: 35333086 DOI: 10.1103/physrevlett.128.102001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 11/29/2021] [Accepted: 02/10/2022] [Indexed: 06/14/2023]
Abstract
This article presents groomed jet substructure measurements in pp and Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV with the ALICE detector. The soft drop grooming algorithm provides access to the hard parton splittings inside a jet by removing soft wide-angle radiation. We report the groomed jet momentum splitting fraction, z_{g}, and the (scaled) groomed jet radius, θ_{g}. Charged-particle jets are reconstructed at midrapidity using the anti-k_{T} algorithm with resolution parameters R=0.2 and R=0.4. In heavy-ion collisions, the large underlying event poses a challenge for the reconstruction of groomed jet observables, since fluctuations in the background can cause groomed parton splittings to be misidentified. By using strong grooming conditions to reduce this background, we report these observables fully corrected for detector effects and background fluctuations for the first time. A narrowing of the θ_{g} distribution in Pb-Pb collisions compared to pp collisions is seen, which provides direct evidence of the modification of the angular structure of jets in the quark-gluon plasma. No significant modification of the z_{g} distribution in Pb-Pb collisions compared to pp collisions is observed. These results are compared with a variety of theoretical models of jet quenching, and provide constraints on jet energy-loss mechanisms and coherence effects in the quark-gluon plasma.
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Measurement of Prompt D^{0}, Λ_{c}^{+}, and Σ_{c}^{0,++}(2455) Production in Proton-Proton Collisions at sqrt[s]=13 TeV. PHYSICAL REVIEW LETTERS 2022; 128:012001. [PMID: 35061479 DOI: 10.1103/physrevlett.128.012001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 11/09/2021] [Accepted: 11/24/2021] [Indexed: 06/14/2023]
Abstract
The p_{T}-differential production cross sections of prompt D^{0}, Λ_{c}^{+}, and Σ_{c}^{0,++}(2455) charmed hadrons are measured at midrapidity (|y|<0.5) in pp collisions at sqrt[s]=13 TeV. This is the first measurement of Σ_{c}^{0,++} production in hadronic collisions. Assuming the same production yield for the three Σ_{c}^{0,+,++} isospin states, the baryon-to-meson cross section ratios Σ_{c}^{0,+,++}/D^{0} and Λ_{c}^{+}/D^{0} are calculated in the transverse momentum (p_{T}) intervals 2<p_{T}<12 and 1<p_{T}<24 GeV/c. Values significantly larger than in e^{+}e^{-} collisions are observed, indicating for the first time that baryon enhancement in hadronic collisions also extends to the Σ_{c}. The feed-down contribution to Λ_{c}^{+} production from Σ_{c}^{0,+,++} is also reported and is found to be larger than in e^{+}e^{-} collisions. The data are compared with predictions from event generators and other phenomenological models, providing a sensitive test of the different charm-hadronization mechanisms implemented in the models.
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Measurement of the Cross Sections of Ξ_{c}^{0} and Ξ_{c}^{+} Baryons and of the Branching-Fraction Ratio BR(Ξ_{c}^{0}→Ξ^{-}e^{+}ν_{e})/BR(Ξ_{c}^{0}→Ξ^{-}π^{+}) in pp Collisions at sqrt[s]=13 TeV. PHYSICAL REVIEW LETTERS 2021; 127:272001. [PMID: 35061415 DOI: 10.1103/physrevlett.127.272001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/18/2021] [Accepted: 11/19/2021] [Indexed: 06/14/2023]
Abstract
The p_{T}-differential cross sections of prompt charm-strange baryons Ξ_{c}^{0} and Ξ_{c}^{+} were measured at midrapidity (|y|<0.5) in proton-proton (pp) collisions at a center-of-mass energy sqrt[s]=13 TeV with the ALICE detector at the LHC. The Ξ_{c}^{0} baryon was reconstructed via both the semileptonic decay (Ξ^{-}e^{+}ν_{e}) and the hadronic decay (Ξ^{-}π^{+}) channels. The Ξ_{c}^{+} baryon was reconstructed via the hadronic decay (Ξ^{-}π^{+}π^{+}) channel. The branching-fraction ratio BR(Ξ_{c}^{0}→Ξ^{-}e^{+}ν_{e})/BR(Ξ_{c}^{0}→Ξ^{-}π^{+})=1.38±0.14(stat)±0.22(syst) was measured with a total uncertainty reduced by a factor of about 3 with respect to the current world average reported by the Particle Data Group. The transverse momentum (p_{T}) dependence of the Ξ_{c}^{0}- and Ξ_{c}^{+}-baryon production relative to the D^{0} meson and to the Σ_{c}^{0,+,++}- and Λ_{c}^{+}-baryon production are reported. The baryon-to-meson ratio increases toward low p_{T} up to a value of approximately 0.3. The measurements are compared with various models that take different hadronization mechanisms into consideration. The results provide stringent constraints to these theoretical calculations and additional evidence that different processes are involved in charm hadronization in electron-positron (e^{+}e^{-}) and hadronic collisions.
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Λ_{c}^{+} Production and Baryon-to-Meson Ratios in pp and p-Pb Collisions at sqrt[s_{NN}]=5.02 TeV at the LHC. PHYSICAL REVIEW LETTERS 2021; 127:202301. [PMID: 34860039 DOI: 10.1103/physrevlett.127.202301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 05/27/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
The prompt production of the charm baryon Λ_{c}^{+} and the Λ_{c}^{+}/D^{0} production ratios were measured at midrapidity with the ALICE detector in pp and p-Pb collisions at sqrt[s_{NN}]=5.02 TeV. These new measurements show a clear decrease of the Λ_{c}^{+}/D^{0} ratio with increasing transverse momentum (p_{T}) in both collision systems in the range 2<p_{T}<12 GeV/c, exhibiting similarities with the light-flavor baryon-to-meson ratios p/π and Λ/K_{S}^{0}. At low p_{T}, predictions that include additional color-reconnection mechanisms beyond the leading-color approximation, assume the existence of additional higher-mass charm-baryon states, or include hadronization via coalescence can describe the data, while predictions driven by charm-quark fragmentation processes measured in e^{+}e^{-} and e^{-}p collisions significantly underestimate the data. The results presented in this Letter provide significant evidence that the established assumption of universality (colliding-system independence) of parton-to-hadron fragmentation is not sufficient to describe charm-baryon production in hadronic collisions at LHC energies.
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Experimental Evidence for an Attractive p-ϕ Interaction. PHYSICAL REVIEW LETTERS 2021; 127:172301. [PMID: 34739260 DOI: 10.1103/physrevlett.127.172301] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 09/08/2021] [Accepted: 09/14/2021] [Indexed: 06/13/2023]
Abstract
This Letter presents the first experimental evidence of the attractive strong interaction between a proton and a ϕ meson. The result is obtained from two-particle correlations of combined p-ϕ⊕ p[over ¯]-ϕ pairs measured in high-multiplicity pp collisions at sqrt[s]=13 TeV by the ALICE Collaboration. The spin-averaged scattering length and effective range of the p-ϕ interaction are extracted from the fully corrected correlation function employing the Lednický-Lyuboshits approach. In particular, the imaginary part of the scattering length vanishes within uncertainties, indicating that inelastic processes do not play a prominent role for the p-ϕ interaction. These data demonstrate that the interaction is dominated by elastic p-ϕ scattering. Furthermore, an analysis employing phenomenological Gaussian- and Yukawa-type potentials is conducted. Under the assumption of the latter, the N-ϕ coupling constant is found to be g_{N-ϕ}=0.14±0.03(stat)±0.02(syst). This work provides valuable experimental input to accomplish a self-consistent description of the N-ϕ interaction, which is particularly relevant for the more fundamental studies on partial restoration of chiral symmetry in nuclear medium.
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Characterization and Validation of Fatigue Strains for Superelastic Nitinol Using Digital Image Correlation. J Med Device 2021. [DOI: 10.1115/1.4052012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Abstract
Fatigue is a major challenge encountered in cardiovascular implant design. While the properly heat-treated Nitinol can exhibit up to 6–7% recoverable strains allowing for minimally invasive transcatheter delivery of cardiovascular implants, the cyclic in vivo loading can cause premature fracture of the implant if the fatigue strain is too high. Strain-based criteria have been adopted for the development of Nitinol fatigue resistance. Lacking experimental tools to characterize the local material fatigue strain, fatigue testing of Nitinol specimens has largely relied on the finite element analysis to compute the cyclic strain amplitude and mean strain based on experimentally derived constitutive parameters using phenomenological strain energy theory. Without a consistent computational standard, previous works have resulted in controversy and inconsistency in the impact of mean strain on the fatigue resistance of Nitinol in terms of strain amplitude limit at high cycle fatigue regime. In this paper, digital image correlation (DIC) technique is used to experimentally determine local material strains of Nitinol fatigue specimens using monotonic and cyclic loading conditions. These local strains are compared with strains computed from finite element analysis. It was found that strains from DIC and FEA are comparable in the single-phase states (pure austenitic or martensitic), whereas the measured strains can show significant difference from simulation computed strain during the transformation stage where both austenite and martensite phase co-exist. These observations have significant implications to nitinol fatigue testing and implant reliability assessment.
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Multiharmonic Correlations of Different Flow Amplitudes in Pb-Pb Collisions at sqrt[s_{NN}]=2.76 TeV. PHYSICAL REVIEW LETTERS 2021; 127:092302. [PMID: 34506195 DOI: 10.1103/physrevlett.127.092302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 06/09/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
The event-by-event correlations between three flow amplitudes are measured for the first time in Pb-Pb collisions, using higher-order symmetric cumulants. We find that different three-harmonic correlations develop during the collective evolution of the medium when compared to correlations that exist in the initial state. These new results cannot be interpreted in terms of previous lower-order flow measurements since contributions from two-harmonic correlations are explicitly removed in the new observables. A comparison to Monte Carlo simulations provides new and independent constraints for the initial conditions and system properties of nuclear matter created in heavy-ion collisions.
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Soft-Dielectron Excess in Proton-Proton Collisions at sqrt[s]=13 TeV. PHYSICAL REVIEW LETTERS 2021; 127:042302. [PMID: 34355943 DOI: 10.1103/physrevlett.127.042302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 04/12/2021] [Accepted: 06/08/2021] [Indexed: 06/13/2023]
Abstract
A measurement of dielectron production in proton-proton (pp) collisions at sqrt[s]=13 TeV, recorded with the ALICE detector at the CERN LHC, is presented in this Letter. The data set was recorded with a reduced magnetic solenoid field. This enables the investigation of a kinematic domain at low dielectron (ee) invariant mass m_{ee} and pair transverse momentum p_{T,ee} that was previously inaccessible at the LHC. The cross section for dielectron production is studied as a function of m_{ee}, p_{T,ee}, and event multiplicity dN_{ch}/dη. The expected dielectron rate from hadron decays, called hadronic cocktail, utilizes a parametrization of the measured η/π^{0} ratio in pp and proton-nucleus collisions, assuming that this ratio shows no strong dependence on collision energy at low transverse momentum. Comparison of the measured dielectron yield to the hadronic cocktail at 0.15<m_{ee}<0.6 GeV/c^{2} and for p_{T,ee}<0.4 GeV/c indicates an enhancement of soft dielectrons, reminiscent of the "anomalous" soft-photon and soft-dilepton excess in hadron-hadron collisions reported by several experiments under different experimental conditions. The enhancement factor over the hadronic cocktail amounts to 1.61±0.13(stat)±0.17(syst,data)±0.34(syst,cocktail) in the ALICE acceptance. Acceptance-corrected excess spectra in m_{ee} and p_{T,ee} are extracted and compared with calculations of dielectron production from hadronic bremsstrahlung and thermal radiation within a hadronic many-body approach.
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Elliptic Flow of Electrons from Beauty-Hadron Decays in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV. PHYSICAL REVIEW LETTERS 2021; 126:162001. [PMID: 33961482 DOI: 10.1103/physrevlett.126.162001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 01/27/2021] [Accepted: 03/09/2021] [Indexed: 06/12/2023]
Abstract
The elliptic flow of electrons from beauty hadron decays at midrapidity (|y|<0.8) is measured in Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV with the ALICE detector at the LHC. The azimuthal distribution of the particles produced in the collisions can be parametrized with a Fourier expansion, in which the second harmonic coefficient represents the elliptic flow, v_{2}. The v_{2} coefficient of electrons from beauty hadron decays is measured for the first time in the transverse momentum (p_{T}) range 1.3-6 GeV/c in the centrality class 30%-50%. The measurement of electrons from beauty-hadron decays exploits their larger mean proper decay length cτ≈500 μm compared to that of charm hadrons and most of the other background sources. The v_{2} of electrons from beauty hadron decays at midrapidity is found to be positive with a significance of 3.75 σ. The results provide insights into the degree of thermalization of beauty quarks in the medium. A model assuming full thermalization of beauty quarks is strongly disfavored by the measurement at high p_{T}, but is in agreement with the results at low p_{T}. Transport models including substantial interactions of beauty quarks with an expanding strongly interacting medium describe the measurement within uncertainties.
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Global health inequality and women - beyond maternal health. Anaesthesia 2021; 76 Suppl 4:6-9. [PMID: 33682098 DOI: 10.1111/anae.15431] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2021] [Indexed: 10/22/2022]
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Measurement of the Low-Energy Antideuteron Inelastic Cross Section. PHYSICAL REVIEW LETTERS 2020; 125:162001. [PMID: 33124836 DOI: 10.1103/physrevlett.125.162001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/10/2020] [Accepted: 09/09/2020] [Indexed: 06/11/2023]
Abstract
In this Letter, we report the first measurement of the inelastic cross section for antideuteron-nucleus interactions at low particle momenta, covering a range of 0.3≤p<4 GeV/c. The measurement is carried out using p-Pb collisions at a center-of-mass energy per nucleon-nucleon pair of sqrt[s_{NN}]=5.02 TeV, recorded with the ALICE detector at the CERN LHC and utilizing the detector material as an absorber for antideuterons and antiprotons. The extracted raw primary antiparticle-to-particle ratios are compared to the results from detailed ALICE simulations based on the geant4 toolkit for the propagation of (anti)particles through the detector material. The analysis of the raw primary (anti)proton spectra serves as a benchmark for this study, since their hadronic interaction cross sections are well constrained experimentally. The first measurement of the inelastic cross section for antideuteron-nucleus interactions averaged over the ALICE detector material with atomic mass numbers ⟨A⟩=17.4 and 31.8 is obtained. The measured inelastic cross section points to a possible excess with respect to the Glauber model parametrization used in geant4 in the lowest momentum interval of 0.3≤p<0.47 GeV/c up to a factor 2.1. This result is relevant for the understanding of antimatter propagation and the contributions to antinuclei production from cosmic ray interactions within the interstellar medium. In addition, the momentum range covered by this measurement is of particular importance to evaluate signal predictions for indirect dark-matter searches.
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Probing the Effects of Strong Electromagnetic Fields with Charge-Dependent Directed Flow in Pb-Pb Collisions at the LHC. PHYSICAL REVIEW LETTERS 2020; 125:022301. [PMID: 32701333 DOI: 10.1103/physrevlett.125.022301] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 04/22/2020] [Accepted: 05/19/2020] [Indexed: 06/11/2023]
Abstract
The first measurement at the LHC of charge-dependent directed flow (v_{1}) relative to the spectator plane is presented for Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV. Results are reported for charged hadrons and D^{0} mesons for the transverse momentum intervals p_{T}>0.2 GeV/c and 3<p_{T}<6 GeV/c in the 5%-40% and 10%-40% centrality classes, respectively. The difference between the positively and negatively charged hadron v_{1} has a positive slope as a function of pseudorapidity η, dΔv_{1}/dη=[1.68±0.49(stat)±0.41(syst)]×10^{-4}. The same measurement for D^{0} and D[over ¯]^{0} mesons yields a positive value dΔv_{1}/dη=[4.9±1.7(stat)±0.6(syst)]×10^{-1}, which is about 3 orders of magnitude larger than the one of the charged hadrons. These measurements can provide new insights into the effects of the strong electromagnetic field and the initial tilt of matter created in noncentral heavy ion collisions on the dynamics of light (u, d, and s) and heavy (c) quarks. The large difference between the observed Δv_{1} of charged hadrons and D^{0} mesons may reflect different sensitivity of the charm and light quarks to the early time dynamics of a heavy ion collision. These observations challenge some recent theoretical calculations, which predicted a negative and an order of magnitude smaller value of dΔv_{1}/dη for both light flavor and charmed hadrons.
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Evidence of Spin-Orbital Angular Momentum Interactions in Relativistic Heavy-Ion Collisions. PHYSICAL REVIEW LETTERS 2020; 125:012301. [PMID: 32678650 DOI: 10.1103/physrevlett.125.012301] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 02/25/2020] [Accepted: 05/27/2020] [Indexed: 06/11/2023]
Abstract
The first evidence of spin alignment of vector mesons (K^{*0} and ϕ) in heavy-ion collisions at the Large Hadron Collider (LHC) is reported. The spin density matrix element ρ_{00} is measured at midrapidity (|y|<0.5) in Pb-Pb collisions at a center-of-mass energy (sqrt[s_{NN}]) of 2.76 TeV with the ALICE detector. ρ_{00} values are found to be less than 1/3 (1/3 implies no spin alignment) at low transverse momentum (p_{T}<2 GeV/c) for K^{*0} and ϕ at a level of 3σ and 2σ, respectively. No significant spin alignment is observed for the K_{S}^{0} meson (spin=0) in Pb-Pb collisions and for the vector mesons in pp collisions. The measured spin alignment is unexpectedly large but qualitatively consistent with the expectation from models which attribute it to a polarization of quarks in the presence of angular momentum in heavy-ion collisions and a subsequent hadronization by the process of recombination.
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Scattering Studies with Low-Energy Kaon-Proton Femtoscopy in Proton-Proton Collisions at the LHC. PHYSICAL REVIEW LETTERS 2020; 124:092301. [PMID: 32202883 DOI: 10.1103/physrevlett.124.092301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 12/03/2019] [Accepted: 02/11/2020] [Indexed: 06/10/2023]
Abstract
The study of the strength and behavior of the antikaon-nucleon (K[over ¯]N) interaction constitutes one of the key focuses of the strangeness sector in low-energy quantum chromodynamics (QCD). In this Letter a unique high-precision measurement of the strong interaction between kaons and protons, close and above the kinematic threshold, is presented. The femtoscopic measurements of the correlation function at low pair-frame relative momentum of (K^{+}p⊕K^{-}p[over ¯]) and (K^{-}p⊕K^{+}p[over ¯]) pairs measured in pp collisions at sqrt[s]=5, 7, and 13 TeV are reported. A structure observed around a relative momentum of 58 MeV/c in the measured correlation function of (K^{-}p⊕K^{+}p[over ¯]) with a significance of 4.4σ constitutes the first experimental evidence for the opening of the (K[over ¯]^{0}n⊕K^{0}n[over ¯]) isospin breaking channel due to the mass difference between charged and neutral kaons. The measured correlation functions have been compared to Jülich and Kyoto models in addition to the Coulomb potential. The high-precision data at low relative momenta presented in this work prove femtoscopy to be a powerful complementary tool to scattering experiments and provide new constraints above the K[over ¯]N threshold for low-energy QCD chiral models.
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Measurement of ϒ(1S) Elliptic Flow at Forward Rapidity in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV. PHYSICAL REVIEW LETTERS 2019; 123:192301. [PMID: 31765217 DOI: 10.1103/physrevlett.123.192301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/09/2019] [Indexed: 06/10/2023]
Abstract
The first measurement of the ϒ(1S) elliptic flow coefficient (v_{2}) is performed at forward rapidity (2.5<y<4) in Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV with the ALICE detector at the LHC. The results are obtained with the scalar product method and are reported as a function of transverse momentum (p_{T}) up to 15 GeV/c in the 5%-60% centrality interval. The measured ϒ(1S)v_{2} is consistent with 0 and with the small positive values predicted by transport models within uncertainties. The v_{2} coefficient in 2<p_{T}<15 GeV/c is lower than that of inclusive J/ψ mesons in the same p_{T} interval by 2.6 standard deviations. These results, combined with earlier suppression measurements, are in agreement with a scenario in which the ϒ(1S) production in Pb-Pb collisions at LHC energies is dominated by dissociation limited to the early stage of the collision, whereas in the J/ψ case there is substantial experimental evidence of an additional regeneration component.
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Investigations of Anisotropic Flow Using Multiparticle Azimuthal Correlations in pp, p-Pb, Xe-Xe, and Pb-Pb Collisions at the LHC. PHYSICAL REVIEW LETTERS 2019; 123:142301. [PMID: 31702212 DOI: 10.1103/physrevlett.123.142301] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Indexed: 06/10/2023]
Abstract
Measurements of anisotropic flow coefficients (v_{n}) and their cross-correlations using two- and multiparticle cumulant methods are reported in collisions of pp at sqrt[s]=13 TeV, p-Pb at a center-of-mass energy per nucleon pair sqrt[s_{NN}]=5.02 TeV, Xe-Xe at sqrt[s_{NN}]=5.44 TeV, and Pb-Pb at sqrt[s_{NN}]=5.02 TeV recorded with the ALICE detector. The multiplicity dependence of v_{n} is studied in a very wide range from 20 to 3000 particles produced in the midrapidity region |η|<0.8 for the transverse momentum range 0.2<p_{T}<3.0 GeV/c. An ordering of the coefficients v_{2}>v_{3}>v_{4} is found in pp and p-Pb collisions, similar to that seen in large collision systems, while a weak v_{2} multiplicity dependence is observed relative to nucleus-nucleus collisions in the same multiplicity range. Using a novel subevent method, v_{2} measured with four-particle cumulants is found to be compatible with that from six-particle cumulants in pp and p-Pb collisions. The magnitude of the correlation between v_{n}^{2} and v_{m}^{2}, evaluated with the symmetric cumulants SC(m,n) is observed to be positive at all multiplicities for v_{2} and v_{4}, while for v_{2} and v_{3} it is negative and changes sign for multiplicities below 100, which may indicate a different v_{n} fluctuation pattern in this multiplicity range. The observed long-range multiparticle azimuthal correlations in high multiplicity pp and p-Pb collisions can neither be described by pythia 8 nor by impact-parameter-Glasma, music, and ultrarelativistic quantum molecular dynamics model calculations, and hence, provide new insights into the understanding of collective effects in small collision systems.
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First Observation of an Attractive Interaction between a Proton and a Cascade Baryon. PHYSICAL REVIEW LETTERS 2019; 123:112002. [PMID: 31573229 DOI: 10.1103/physrevlett.123.112002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 06/28/2019] [Indexed: 06/10/2023]
Abstract
This Letter presents the first experimental observation of the attractive strong interaction between a proton and a multistrange baryon (hyperon) Ξ^{-}. The result is extracted from two-particle correlations of combined p-Ξ^{-}⊕p[over ¯]-Ξ[over ¯]^{+} pairs measured in p-Pb collisions at sqrt[s_{NN}]=5.02 TeV at the LHC with ALICE. The measured correlation function is compared with the prediction obtained assuming only an attractive Coulomb interaction and a standard deviation in the range [3.6, 5.3] is found. Since the measured p-Ξ^{-}⊕p[over ¯]-Ξ[over ¯]^{+} correlation is significantly enhanced with respect to the Coulomb prediction, the presence of an additional, strong, attractive interaction is evident. The data are compatible with recent lattice calculations by the HAL-QCD Collaboration, with a standard deviation in the range [1.8, 3.7]. The lattice potential predicts a shallow repulsive Ξ^{-} interaction within pure neutron matter and this implies stiffer equations of state for neutron-rich matter including hyperons. Implications of the strong interaction for the modeling of neutron stars are discussed.
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Land use and land cover change effect on surface temperature over Eastern India. Sci Rep 2019; 9:8859. [PMID: 31222135 PMCID: PMC6586851 DOI: 10.1038/s41598-019-45213-z] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 06/03/2019] [Indexed: 11/18/2022] Open
Abstract
Land use and land cover (LULC) change has been shown to have significant effect on climate through various pathways that modulate land surface temperature and rainfall. However, few studies have illustrated such a link over the Indian region using observations. Through a combination of ground, satellite remote sensing and reanalysis products, we investigate the recent changes to land surface temperature in the Eastern state of Odisha between 1981 and 2010 and assess its relation to LULC. Our analysis reveals that the mean temperature of the state has increased by ~0.3 °C during the past three decades with the most accelerated warming (~0.9 °C) occurring during the recent decade (2001 to 2010). Our study shows that 25 to 50% of this observed overall warming is associated with LULC. Further we observe that the spatial pattern of LULC changes matches well with the independently estimated warming associated with LULC suggesting a physical association between them. This study also reveals that the largest changes are linked to changing vegetation cover as evidenced by changes to both LULC classes and normalized difference vegetation index (NDVI). Our study shows that the state has undergone an LULC induced warming which accounts for a quarter of the overall temperature rise since 2001. With the expected expansion of urban landscape and concomitant increase in anthropogenic activities along with changing cropping patterns, LULC linked changes to surface temperature and hence regional climate feedback over this region necessitates additional investigations.
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SUN-192 Functional Interactions between Estrogen and Relaxin Signaling in the Myometrium. J Endocr Soc 2019. [PMCID: PMC6553310 DOI: 10.1210/js.2019-sun-192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The complex interplay between the steroid hormones progesterone and estrogen (E2), acting through their cognate nuclear receptors, coordinates uterine myometrial contractility. Upon binding E2, estrogen receptor alpha (ERα) binds to regulatory elements across the genome, and promotes the assembly of transcriptional enhancers. The E2-induced ERα (i.e., cistrome) is plastic, and can be reconfigured in response to activation by other cellular signaling pathways. In addition to steroid hormones, the peptide hormone relaxin (Rln), acting via its G-protein coupled receptor, Rxfp1, has numerous, well described roles in the physiology of pregnancy. Interestingly, many of the effects of Rln require, or are augmented by E2 signaling through ERα. However, the extent, and molecular mechanisms by which cross-talk between E2 and Rln is achieved to ensure myometrial function is unknown. We hypothesized that Rln signaling in the myometrium alters or regulates a parturition-specific ERα cistrome that results in a cell-specific and dynamic altered transcriptome that controls downstream biological events. We used myometrial tissue from ovariectomized (ovx) mice treated with E2+Rln or either hormone alone, or from pregnant mice with or without a targeted deletion of Rxfp1. We generated high quality cistromic (ChIP-seq) and transcriptomic (RNA-seq) data sets in the ovx mouse model. The RNA-seq data sets have uncovered a unique transcriptome signature regulated by combined actions of E2 and Rln in the myometrium. In addition, we observed that many of the ERα binding sites were depleted in the presence of Rln, although histone modification associated with active enhancers (i.e., H3K27ac, and H3K4me1) were still enriched at those sites. The reduction in ERα binding is not explained by a reduction in ERα protein, as total ERα protein does not change across these treatments. In contrast, specific phosphorylation sites on ERα regulated by kinases were changed across these treatments. We also observed increased Erk1/2 activation with E2+Rln in the ovx mouse system compared to either hormone alone. Consistent with this observation, myometrial Erk1/2 activation is elevated in late pregnancy in wild type mice, but not in the Rxfp1 KO mouse. Current studies are underway to assess Erk1/2 signaling as a potential downstream mediator of Rln that alters the ERα activity, and also chromatin accessibility to direct the E2/ERa transcriptome signature for appropriate uterine function. This work is supported by theGreenCenterTrainingPrograminReproductiveBiologyScience Research.
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Azimuthal Anisotropy of Heavy-Flavor Decay Electrons in p-Pb Collisions at sqrt[s_{NN}]=5.02 TeV. PHYSICAL REVIEW LETTERS 2019; 122:072301. [PMID: 30848618 DOI: 10.1103/physrevlett.122.072301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 10/16/2018] [Indexed: 06/09/2023]
Abstract
Angular correlations between heavy-flavor decay electrons and charged particles at midrapidity (|η|<0.8) are measured in p-Pb collisions at sqrt[s_{NN}]=5.02 TeV. The analysis is carried out for the 0%-20% (high) and 60%-100% (low) multiplicity ranges. The jet contribution in the correlation distribution from high-multiplicity events is removed by subtracting the distribution from low-multiplicity events. An azimuthal modulation remains after removing the jet contribution, similar to previous observations in two-particle angular correlation measurements for light-flavor hadrons. A Fourier decomposition of the modulation results in a positive second-order coefficient (v_{2}) for heavy-flavor decay electrons in the transverse momentum interval 1.5<p_{T}<4 GeV/c in high-multiplicity events, with a significance larger than 5σ. The results are compared with those of charged particles at midrapidity and those of inclusive muons at forward rapidity. The v_{2} measurement of open heavy-flavor particles at midrapidity in small collision systems could provide crucial information to help interpret the anisotropies observed in such systems.
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Image Gallery: Folliculocystic and collagen hamartoma: a lesser‐known presentation of tuberous sclerosis. Br J Dermatol 2018; 178:e276. [DOI: 10.1111/bjd.16359] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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D-Meson Azimuthal Anisotropy in Midcentral Pb-Pb Collisions at sqrt[s]_{NN}=5.02 TeV. PHYSICAL REVIEW LETTERS 2018; 120:102301. [PMID: 29570314 DOI: 10.1103/physrevlett.120.102301] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Revised: 11/16/2017] [Indexed: 06/08/2023]
Abstract
The azimuthal anisotropy coefficient v_{2} of prompt D^{0}, D^{+}, D^{*+}, and D_{s}^{+} mesons was measured in midcentral (30%-50% centrality class) Pb-Pb collisions at a center-of-mass energy per nucleon pair sqrt[s_{NN}]=5.02 TeV, with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decays at midrapidity, |y|<0.8, in the transverse momentum interval 1<p_{T}<24 GeV/c. The measured D-meson v_{2} has similar values as that of charged pions. The D_{s}^{+} v_{2}, measured for the first time, is found to be compatible with that of nonstrange D mesons. The measurements are compared with theoretical calculations of charm-quark transport in a hydrodynamically expanding medium and have the potential to constrain medium parameters.
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J/ψ Elliptic Flow in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV. PHYSICAL REVIEW LETTERS 2017; 119:242301. [PMID: 29286736 DOI: 10.1103/physrevlett.119.242301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Indexed: 06/07/2023]
Abstract
We report a precise measurement of the J/ψ elliptic flow in Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV with the ALICE detector at the LHC. The J/ψ mesons are reconstructed at midrapidity (|y|<0.9) in the dielectron decay channel and at forward rapidity (2.5<y<4.0) in the dimuon channel, both down to zero transverse momentum. At forward rapidity, the elliptic flow v_{2} of the J/ψ is studied as a function of the transverse momentum and centrality. A positive v_{2} is observed in the transverse momentum range 2<p_{T}<8 GeV/c in the three centrality classes studied and confirms with higher statistics our earlier results at sqrt[s_{NN}]=2.76 TeV in semicentral collisions. At midrapidity, the J/ψ v_{2} is investigated as a function of the transverse momentum in semicentral collisions and found to be in agreement with the measurements at forward rapidity. These results are compared to transport model calculations. The comparison supports the idea that at low p_{T} the elliptic flow of the J/ψ originates from the thermalization of charm quarks in the deconfined medium but suggests that additional mechanisms might be missing in the models.
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Impact of Rapid Urbanization on the City of Bhubaneswar, India. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES INDIA SECTION A-PHYSICAL SCIENCES 2017. [DOI: 10.1007/s40010-017-0453-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Anomalous Evolution of the Near-Side Jet Peak Shape in Pb-Pb Collisions at sqrt[s_{NN}]=2.76 TeV. PHYSICAL REVIEW LETTERS 2017; 119:102301. [PMID: 28949169 DOI: 10.1103/physrevlett.119.102301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Indexed: 06/07/2023]
Abstract
The measurement of two-particle angular correlations is a powerful tool to study jet quenching in a p_{T} region inaccessible by direct jet identification. In these measurements pseudorapidity (Δη) and azimuthal (Δφ) differences are used to extract the shape of the near-side peak formed by particles associated with a higher p_{T} trigger particle (1<p_{T,trig}<8 GeV/c). A combined fit of the near-side peak and long-range correlations is applied to the data allowing the extraction of the centrality evolution of the peak shape in Pb-Pb collisions at sqrt[s_{NN}]=2.76 TeV. A significant broadening of the peak in the Δη direction at low p_{T} is found from peripheral to central collisions, which vanishes above 4 GeV/c, while in the Δφ direction the peak is almost independent of centrality. For the 10% most central collisions and 1<p_{T,assoc}<2 GeV/c, 1<p_{T,trig}<3 GeV/c a novel feature is observed: a depletion develops around the center of the peak. The results are compared to pp collisions at the same center of mass energy and ampt model simulations. The comparison to the investigated models suggests that the broadening and the development of the depletion is connected to the strength of radial and longitudinal flow.
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Energy dependence of forward-rapidity [Formula: see text] and [Formula: see text] production in pp collisions at the LHC. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2017; 77:392. [PMID: 28775665 PMCID: PMC5512511 DOI: 10.1140/epjc/s10052-017-4940-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 05/24/2017] [Indexed: 06/07/2023]
Abstract
We present results on transverse momentum ([Formula: see text]) and rapidity ([Formula: see text]) differential production cross sections, mean transverse momentum and mean transverse momentum square of inclusive [Formula: see text] and [Formula: see text] at forward rapidity ([Formula: see text]) as well as [Formula: see text]-to-[Formula: see text] cross section ratios. These quantities are measured in pp collisions at center of mass energies [Formula: see text] and 13 TeV with the ALICE detector. Both charmonium states are reconstructed in the dimuon decay channel, using the muon spectrometer. A comprehensive comparison to inclusive charmonium cross sections measured at [Formula: see text], 7 and 8 TeV is performed. A comparison to non-relativistic quantum chromodynamics and fixed-order next-to-leading logarithm calculations, which describe prompt and non-prompt charmonium production respectively, is also presented. A good description of the data is obtained over the full [Formula: see text] range, provided that both contributions are summed. In particular, it is found that for [Formula: see text] GeV/c the non-prompt contribution reaches up to 50% of the total charmonium yield.
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Production of Σ(1385)± and Ξ(1530)0 in p-Pb collisions at sNN=5.02 TeV. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2017; 77:389. [PMID: 29430210 PMCID: PMC5797483 DOI: 10.1140/epjc/s10052-017-4943-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 05/24/2017] [Indexed: 06/08/2023]
Abstract
The transverse momentum distributions of the strange and double-strange hyperon resonances (Σ ( 1385 ) ± , Ξ ( 1530 ) 0 ) produced in p-Pb collisions at s NN = 5.02 TeV were measured in the rapidity range - 0.5 < y CMS < 0 for event classes corresponding to different charged-particle multiplicity densities, ⟨ dN ch /dη lab ⟩ . The mean transverse momentum values are presented as a function of ⟨ dN ch /dη lab ⟩ , as well as a function of the particle masses and compared with previous results on hyperon production. The integrated yield ratios of excited to ground-state hyperons are constant as a function of ⟨ dN ch /dη lab ⟩ . The equivalent ratios to pions exhibit an increase with ⟨ dN ch /dη lab ⟩ , depending on their strangeness content.
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Production of [Formula: see text] and [Formula: see text] mesons up to high transverse momentum in pp collisions at 2.76 TeV. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2017; 77:339. [PMID: 28943788 PMCID: PMC5586361 DOI: 10.1140/epjc/s10052-017-4890-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 05/05/2017] [Indexed: 06/07/2023]
Abstract
The invariant differential cross sections for inclusive [Formula: see text] and [Formula: see text] mesons at midrapidity were measured in pp collisions at [Formula: see text] TeV for transverse momenta [Formula: see text] GeV/c and [Formula: see text] GeV/c, respectively, using the ALICE detector. This large range in [Formula: see text] was achieved by combining various analysis techniques and different triggers involving the electromagnetic calorimeter (EMCal). In particular, a new single-cluster, shower-shape based method was developed for the identification of high-[Formula: see text] neutral pions, which exploits that the showers originating from their decay photons overlap in the EMCal. Above 4 GeV/[Formula: see text], the measured cross sections are found to exhibit a similar power-law behavior with an exponent of about 6.3. Next-to-leading-order perturbative QCD calculations differ from the measured cross sections by about 30% for the [Formula: see text], and between 30-50% for the [Formula: see text] meson, while generator-level simulations with PYTHIA 8.2 describe the data to better than 10-30%, except at [Formula: see text] GeV/[Formula: see text]. The new data can therefore be used to further improve the theoretical description of [Formula: see text] and [Formula: see text] meson production.
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Flow Dominance and Factorization of Transverse Momentum Correlations in Pb-Pb Collisions at the LHC. PHYSICAL REVIEW LETTERS 2017; 118:162302. [PMID: 28474923 DOI: 10.1103/physrevlett.118.162302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Indexed: 06/07/2023]
Abstract
We present the first measurement of the two-particle transverse momentum differential correlation function, P_{2}≡⟨Δp_{T}Δp_{T}⟩/⟨p_{T}⟩^{2}, in Pb-Pb collisions at sqrt[s_{NN}]=2.76 TeV. Results for P_{2} are reported as a function of the relative pseudorapidity (Δη) and azimuthal angle (Δφ) between two particles for different collision centralities. The Δϕ dependence is found to be largely independent of Δη for |Δη|≥0.9. In the 5% most central Pb-Pb collisions, the two-particle transverse momentum correlation function exhibits a clear double-hump structure around Δφ=π (i.e., on the away side), which is not observed in number correlations in the same centrality range, and thus provides an indication of the dominance of triangular flow in this collision centrality. Fourier decompositions of P_{2}, studied as a function of the collision centrality, show that correlations at |Δη|≥0.9 can be well reproduced by a flow ansatz based on the notion that measured transverse momentum correlations are strictly determined by the collective motion of the system.
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