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1.
Phys Rev Lett ; 132(17): 172302, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38728735

RESUMO

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

2.
Phys Rev Lett ; 132(22): 222303, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38877919

RESUMO

K^{+}K^{-} pairs may be produced in photonuclear collisions, either from the decays of photoproduced ϕ(1020) mesons or directly as nonresonant K^{+}K^{-} pairs. Measurements of K^{+}K^{-} photoproduction probe the couplings between the ϕ(1020) and charged kaons with photons and nuclear targets. The kaon-proton scattering occurs at energies far above those available elsewhere. We present the first measurement of coherent photoproduction of K^{+}K^{-} pairs on lead ions in ultraperipheral collisions using the ALICE detector, including the first investigation of direct K^{+}K^{-} production. There is significant K^{+}K^{-} production at low transverse momentum, consistent with coherent photoproduction on lead targets. In the mass range 1.1

3.
Phys Rev Lett ; 132(16): 162302, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38701458

RESUMO

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.

4.
Phys Rev Lett ; 133(2): 022301, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-39073970

RESUMO

The ALICE Collaboration reports the measurement of semi-inclusive distributions of charged-particle jets recoiling from a high transverse momentum (high p_{T}) hadron trigger in proton-proton and central Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV. A data-driven statistical method is used to mitigate the large uncorrelated background in central Pb-Pb collisions. Recoil jet distributions are reported for jet resolution parameter R=0.2, 0.4, and 0.5 in the range 7

5.
Phys Rev Lett ; 133(9): 092301, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39270180

RESUMO

This Letter presents the most precise measurement to date of the matter-antimatter imbalance at midrapidity in Pb-Pb collisions at a center-of-mass energy per nucleon pair sqrt[s_{NN}]=5.02 TeV. Using the Statistical Hadronization framework, it is possible to obtain the value of the electric charge and baryon chemical potentials, µ_{Q}=-0.18±0.90 MeV and µ_{B}=0.71±0.45 MeV, with unprecedented precision. A centrality-differential study of the antiparticle-to-particle yield ratios of charged pions, protons, Ω baryons, and light (hyper)nuclei is performed. These results indicate that the system created in Pb-Pb collisions at the LHC is on average baryon-free and electrically neutral at midrapidity.

6.
Phys Rev Lett ; 132(4): 042301, 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38335364

RESUMO

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

7.
BMC Urol ; 24(1): 7, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38172746

RESUMO

BACKGROUND: To discuss the impact of overactive bladder (OAB) on medical students. overactive bladder. is a chronic condition that causes sudden and intense urges to urinate, which can have significant physical and psychological effects on patients' lives. The prevalence of OAB among medical students is relatively high, with some studies reporting rates as high as 35.4%. This research aims to shed light on the prevalence rates and risk factors associated with OAB among medical students in Jordan. METHODS: A cross-sectional study was conducted using an online self-reported questionnaire as the study tool. The questionnaire collected the sociodemographic, health, and academic characteristics of medical students, as well as the new 7-item OABSS score. RESULTS: Out of the total sample of medical students surveyed (n = 525), 44.5% reported experiencing symptoms of OAB. Furthermore, the analysis also revealed that there was a significant difference in the prevalence of OAB between the ages of medical students. In addition, the study also found that there was a significant association between OAB symptoms and basic years, positive history of diagnostic UTI, positive history of recent trauma, high stress, and taking certain medications. CONCLUSIONS: The study highlights the need for further research in this area and emphasizes the possible implications of OAB for medical students, including the need for additional support and resources to manage the condition.


Assuntos
Estudantes de Medicina , Bexiga Urinária Hiperativa , Humanos , Bexiga Urinária Hiperativa/tratamento farmacológico , Estudos Transversais , Prevalência , Jordânia/epidemiologia , Fatores de Risco , Inquéritos e Questionários
8.
Med J Malaysia ; 79(3): 296-305, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38817062

RESUMO

INTRODUCTION: The efficacy of long-course corticosteroid therapy in treating COVID-19-related diffuse interstitial lung abnormalities (DILA) needs to be better understood. We aimed to investigate the benefits of 12-week corticosteroid treatment in COVID-19-related DILA by evaluating computed tomography (CT) lung severity scores. MATERIALS AND METHODS: This retrospective, single-centre observational study included patients aged 18 years or older admitted with moderate to severe COVID-19 pneumonia who received 12 weeks of oral prednisolone between January 2021 and December 2021. We recorded clinical parameters, baseline CT scores and post-treatment, modified Medical Research Council (mMRC) dyspnoea scale and pulmonary function tests. RESULTS: A total of 330 patients were analysed. The mean (standard deviation, SD) age was 54.6 (14.2) years, and 43% were females. Three-point nine per cent (3.9%) require noninvasive ventilation (NIV), while 14.6% require mechanical ventilation (MV). On follow-up at 12 weeks, the CT patterns showed improvement in ground-glass opacities, perilobular density and consolidation. There was an improvement in the mean (SD) CT score before and after prednisolone therapy, with values of 17.3 (5.3) and 8.6 (5.5), respectively (p<0.001). The median mMRC was 1 (IQR 0-1), and 98.8% had a radiological response. The common side effects of prednisolone therapy were weight gain (13.9%), hyperglycaemia (1.8%) and cushingoid habitus (0.6%). CONCLUSION: A 12-week treatment with prednisolone showed significant improvement in CT scores with minimal residual dyspnoea and was relatively safe. Longer duration of steroids may be beneficial in moderate to severe COVID-19- related DILA.


Assuntos
COVID-19 , Doenças Pulmonares Intersticiais , Prednisolona , Tomografia Computadorizada por Raios X , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , COVID-19/complicações , Adulto , Doenças Pulmonares Intersticiais/tratamento farmacológico , Doenças Pulmonares Intersticiais/etiologia , Idoso , Prednisolona/administração & dosagem , Prednisolona/uso terapêutico , Resultado do Tratamento , Tratamento Farmacológico da COVID-19 , SARS-CoV-2 , Corticosteroides/uso terapêutico , Corticosteroides/administração & dosagem , Glucocorticoides/administração & dosagem , Glucocorticoides/uso terapêutico , Índice de Gravidade de Doença
9.
Phys Rev Lett ; 131(4): 042303, 2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37566833

RESUMO

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

10.
Phys Rev Lett ; 131(4): 042301, 2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37566840

RESUMO

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.

11.
Phys Rev Lett ; 131(4): 041901, 2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37566856

RESUMO

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.

12.
Phys Rev Lett ; 131(19): 192301, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-38000395

RESUMO

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.

13.
Phys Rev Lett ; 131(10): 102302, 2023 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-37739380

RESUMO

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.

14.
Med J Malaysia ; 78(1): 25-31, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36715187

RESUMO

INTRODUCTION: The under-five mortality (U5M) trend in Malaysia significantly declined from 30.0 per 1000 live births (1980) to 8.0 per 1000 live births (2004), and the trend plateaued over the next two decades. Stillbirths and neonatal deaths were the major contributors to U5M. Scarce literature addressing factors associated with preventable U5M in Malaysia. The objective of this study was to describe preventable stillbirths and neonatal mortality, the associated factors and recommendation for improvement. MATERIALS AND METHODS: The U5M surveillance data from 2015 to 2017 was retrieved for Malaysian cases of stillbirths and neonatal deaths with multiple pregnancies as exclusion. Stillbirth and neonatal death cases were analysed descriptively for socio-demographic and clinical characteristics. Logistic regressions were performed to identify the associated factors. RESULTS: There were 15,444 cases selected for analysis, of which 55% of stillbirths and 45% of neonatal deaths. There were 21% of preventable deaths (U5M) and the major contributing causes of preventable stillbirths and neonatal deaths were classified as perinatal death (82.5%), infectious and parasitic diseases (4.1%) and congenital malformations (3.5%). The birth weight (aOR 6.03, 95% CI: 4.14-8.79), hypertensive mother (aOR 1.88, 95% CI: 1.66-2.12) and instrumental delivery (aOR 1.64, 95% CI: 1.16-2.31) were significantly associated with preventable stillbirths and neonatal deaths. Higher household income (>RM3000 per month) was noted as a protective factor (aOR 0.79, 95% CI:0.69,0.89). Mothers with ethnicities other thanBumiputera, single mothers and housewives were identified as the group of mothers with higher odds of poor perinatal services. Among the 3242 cases of preventable stillbirths and neonatal deaths with a complete documented level of adequacy and quality of healthcare, the most frequently identified factors were due to insufficient antenatal care (ANC) (20.4%), non-compliance with medical advice (12.3%) and unsuitable place of delivery (8.6%). CONCLUSION: Increasing trend of preventable stillbirths and neonatal deaths was noted over 3 years (2015-2017), and one-fifth was related to insufficient ANC service-related factors. Remedial measures in improving the quality of ANC services with an emphasis on the targeted high-risk maternal socio-demographic group (other Bumiputera, older antenatal mothers, nonmarried, poor family income neglected family) and enhancing ANC competency skills among the healthcare provider through adequate training are required to decrease preventable stillbirths and neonatal deaths in Malaysia.


Assuntos
Morte Perinatal , Natimorto , Recém-Nascido , Gravidez , Feminino , Humanos , Natimorto/epidemiologia , Morte Perinatal/etiologia , Morte Perinatal/prevenção & controle , Malásia/epidemiologia , Mortalidade Infantil , Mães
15.
Med J Malaysia ; 78(6): 787-792, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38031222

RESUMO

INTRODUCTION: In Malaysia, studies on self-reported bone fractures are scarce. Due to the fact that bone fractures may serve as an indicator of osteoporosis in the community, this study aimed to identify the factors associated with their occurrence among adults in Malaysia. MATERIALS AND METHODS: Epidemiological data for selfreported bone fractures were obtained through direct interviews using a validated questionnaire from the Prospective Urban and Rural Epidemiology (PURE) study. RESULTS: Of 15,378 respondents, 6.63% (n=1019) reported bone fractures, with a higher proportion of men (65.8%, n=671) than women (34.2%, n=348). Higher odds of selfreporting bone fractures were seen in males (aOR, 2.12; 95%CI: 1.69, 2.65), those with a history of injury (aOR 5.01; 95%CI: 3.10, 6.32) and those who were obese (aOR: 1.46; 95% CI: 1.13, 1.89), highly active (aOR 1.25; 95%CI: 1.02, 1.53), smokers (aOR 1.35; 95%CI: 1.11, 1.65) and alcohol consumers (aOR 1.67; 95%CI: 1.20,2.32). CONCLUSION: Adopting a healthier lifestyle that includes a balanced diet and moderate physical activity is critical for weight loss, increased muscle and bone mass and better stability, which reduces the likelihood of fractures following a fall.


Assuntos
Fraturas Ósseas , Masculino , Humanos , Adulto , Feminino , Autorrelato , Malásia/epidemiologia , Estudos Prospectivos , Estudos de Coortes , Fraturas Ósseas/epidemiologia , Fraturas Ósseas/etiologia , Fatores de Risco
16.
Phys Rev Lett ; 128(1): 012001, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-35061479

RESUMO

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

17.
Phys Rev Lett ; 128(25): 252003, 2022 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-35802430

RESUMO

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

18.
Phys Rev Lett ; 128(17): 172005, 2022 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-35570422

RESUMO

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.

19.
Phys Rev Lett ; 128(10): 102001, 2022 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-35333086

RESUMO

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.

20.
Med J Malaysia ; 77(1): 104-106, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35087006

RESUMO

This is the first reported case of a mesenteric lymphatic malformation in a toddler in Malaysia. It is a rare benign condition with incidence of 1 in 250,000 populations. Our patient presented to us at 2 years 11months old complaining of abdominal distension for 6 months without obstructive symptoms. Clinically there was a vague soft central abdominal mass. CT abdomen done revealed a large multiloculated intraperitoneal mesentery cystic mass within the central abdomen extending to pelvis. A semi-emergency laparotomy was performed. Intra-operatively the multiloculated mesenteric cyst measured 20cm x 30cm, adherent to the small bowel beginning at 12cm from duodeno-jejunal junction. Resection of the mesenteric cyst with adherent small bowel and primary anastomosis was done. Histopathological examination revealed multiple large lymphatic channels of various sizes in the mucosa and submucosa. Our patient has no signs of recurrence and remains symptom-free after 1 year since his surgery. Surgery with clear margins of resection is the recommended gold standard based on available literature. Type of surgical resection required will depend on the type of mesenteric lymphatic malformation. An awareness of this rare pathology is required to ensure proper management is given to these patients.


Assuntos
Anormalidades Linfáticas , Cisto Mesentérico , Pré-Escolar , Humanos , Laparotomia , Anormalidades Linfáticas/cirurgia , Malásia , Cisto Mesentérico/cirurgia , Mesentério/patologia , Mesentério/cirurgia
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