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1.
Med J Malaysia ; 79(2): 184-190, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38553924

RESUMO

INTRODUCTION: Hypoxic ischemic encephalopathy (HIE) is a clinically defined syndrome of disturbed neurologic function in the newborn with evidence of perinatal asphyxia. Stages of HIE are categorised into mild, moderate or severe based on the Sarnat classification. Neurological dysfunction constitutes a part of the wide spectrum of hypoxic ischemic insult as affected infants can have co-existing multi-organ dysfunction which further contributes to morbidities and mortality. This study aims to determine the relationship between the severity of HIE with multi-organ complications and early clinical outcomes. MATERIALS AND METHODS: All neonates who were admitted to the NICU at Hospital Sultan Abdul Halim between January 2018 to December 2022, who fulfilled the inclusion criteria were included. Demographic data, clinical course and investigation results were retrospectively obtained from the medical records. RESULTS: From a total of 90 infants (n = 90) who fulfilled our inclusion criteria, 31 (34%) were mild, 31 (34%) were moderate and 28 (31%) were severe HIE. The mean maternal age was 27 years. Common antenatal issues include diabetes mellitus (37.8%) and anaemia (22.2%). The Apgar scores at 1 and 5 minutes, initial resuscitation requiring intubation, chest compression and adrenaline were associated with higher severity of HIE (p < 0.05). Coagulation dysfunction was the most common complication (79.7%), followed by respiratory dysfunction (33.3%), cardiac dysfunction (28.9%), renal dysfunction (16.1%), haematological dysfunction (15.6%) and hepatic dysfunction (12%). Respiratory and haematological dysfunctions were significantly associated with higher mortality (p < 0.05). There was a significant longer hospital stay (p = 0.023), longer duration of ventilation (p < 0.001) and increase in frequency of seizures (p < 0.001) when comparing moderate and severe HIE patients to mild HIE patients. With increasing severity of HIE, there was also statistically significant higher mortality (p < 0.001). CONCLUSIONS: There is a significant relationship between multiorgan dysfunction, the severity of HIE and mortality. Early anticipation of multi-organ injury is crucial for optimal early management which would reduce the mortality and improve the neurological outcome of the patients.


Assuntos
Asfixia Neonatal , Hipóxia-Isquemia Encefálica , Recém-Nascido , Lactente , Humanos , Feminino , Gravidez , Adulto , Hipóxia-Isquemia Encefálica/complicações , Hipóxia-Isquemia Encefálica/terapia , Estudos Retrospectivos , Hospitais de Distrito , Hipóxia , Asfixia Neonatal/complicações
2.
Tech Coloproctol ; 28(1): 10, 2023 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-38091118

RESUMO

BACKGROUND: A common and debilitating complication of low anterior resection for rectal cancer is low anterior resection syndrome (LARS). As a multifactorial entity, LARS is poorly understood and challenging to treat. Despite this, prevention strategies are commonly overlooked. Our aim was to review the pathophysiology of LARS and explore current evidence on the efficacy and feasibility of prophylactic techniques. METHODS: A literature review was performed between [1st January 2000 to 1st October 2023] for studies which investigated preventative interventions for LARS. Mechanisms by which LARS develop are described, followed by a review of prophylactic strategies to prevent LARS. Medline, Cochrane, and PubMed databases were searched, 189 articles screened, 8 duplicates removed and 18 studies reviewed. RESULTS: Colonic dysmotility, anal sphincter dysfunction and neorectal dysfunction all contribute to the development of LARS, with the complex mechanism of defecation interrupted by surgery. Transanal irrigation (TAI) and pelvic floor rehabilitation (PFR) have shown benefits in preventing LARS, but may be limited by patient compliance. Intraoperative nerve monitoring (IONM) and robotic-assisted surgery have shown some promise in surgically preventing LARS. Nerve stimulation and other novel strategies currently used in treatment of LARS have yet to be investigated in their roles prophylactically. CONCLUSIONS: To date, there is a limited evidence base for all preventative strategies including IONM, RAS, PFP and TAI. These strategies are limited by either access (IONM, RAS and PFP) or acceptability (PFP and TAI), which are both key to the success of any intervention. The results of ongoing trials will serve to assess acceptability, while technological advancement may improve access to some of the aforementioned strategies.


Assuntos
Neoplasias Retais , Procedimentos Cirúrgicos Robóticos , Humanos , Canal Anal/cirurgia , Síndrome de Ressecção Anterior Baixa , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Qualidade de Vida , Neoplasias Retais/cirurgia , Neoplasias Retais/complicações , Procedimentos Cirúrgicos Robóticos/efeitos adversos
3.
Malays J Pathol ; 45(2): 247-259, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37658534

RESUMO

INTRODUCTION: Mesenchymal stromal cells (MSCs) are promising vehicles for cancer therapy due to their homing ability and potency to be genetically manipulated through either viral or non-viral methods. Interleukin-12 (IL-12) is one of the key immunomodulatory cytokines which has anti-tumour effect. However, systemic administration of the cytokine at therapeutic dosage can cause serious toxicity in the host system due to the high systemic level of interferon-γ (IFN-γ) induced. OBJECTIVES: This study aimed to investigate the in vitro growth inhibition of genetically engineered human umbilical cord-derived mesenchymal stromal cells (hUCMSC) expressing IL-12 on H1975 human lung adenocarcinoma cells. MATERIALS AND METHODS: Both adenoviral method and electroporation which used to generate hUCMSC-IL12 were compared. The method with better outcome was selected to generate hUCMSC-IL12 for the co-culture experiment with H1975 or MRC-5 cells. Characterisation of hUCMSC and hUCMSC-IL12 was performed. RESULTS: Adenoviral method showed superior results in transfection efficiency (63.6%), post-transfection cell viability (82.6%) and hIL-12 protein expression (1.2 x 107 pg/ml) and thus was selected for the downstream experiments. Subsequently, hUCMSC-IL12 showed significant inhibition effect on H1975 cells after 5 days of co-culture. No significant difference was observed for all other co-culture groups, indicating that the inhibition effect was because of hIL-12. Lastly, the integrity of hUCMSC-IL12 remained unaffected by the transduction through examination of their surface markers and differentiation properties. CONCLUSION: This study provided proof of concept that hUCMSC can be genetically engineered to express hIL-12 which exerts direct growth inhibition effect on human lung adenocarcinoma cells.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Células-Tronco Mesenquimais , Humanos , Interleucina-12/genética , Citocinas
4.
Opt Express ; 30(26): 47909-47920, 2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36558708

RESUMO

Liquid crystals are of great interest in the field of nonlinear optics due to their efficient response to low intensity light fields. Here we present a new, to the best of our knowledge, mechanism of a nonlinear optical response which is observed for a dye-doped dual-frequency nematic liquid crystal. The local increase in temperature caused by the absorption of light beam in the liquid crystal medium leads to spatial variation and inversion of the sign of the dielectric anisotropy. When an alternating current electric field with a frequency close to the cross-over frequency is applied to the liquid crystal cell, the planar orientation sustains at the beam periphery, but elastic deformation occurs in the irradiation region. In the case of a dye dopant with negative absorption dichroism, a first-order orientational transition with large bistability region is obtained.

5.
Phys Rev Lett ; 129(14): 142502, 2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36240396

RESUMO

The root mean square radii of the proton density distribution in ^{16-24}O derived from measurements of charge changing cross sections with a carbon target at ∼900A MeV together with the matter radii portray thick neutron skin for ^{22-24}O despite ^{22,24}O being doubly magic. Imprints of the shell closures at N=14 and 16 are reflected in local minima of their proton radii that provide evidence for the tensor interaction causing them. The radii agree with ab initio calculations employing the chiral NNLO_{sat} interaction, though skin thickness predictions are challenged. Shell model predictions agree well with the data.


Assuntos
Nêutrons , Prótons , Carbono
6.
Phys Rev Lett ; 128(24): 242502, 2022 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-35776479

RESUMO

The isomer depletion of ^{93m}Mo was recently reported [Chiara et al., Nature (London) 554, 216 (2018)NATUAS0028-083610.1038/nature25483] as the first direct observation of nuclear excitation by electron capture (NEEC). However, the measured excitation probability of 1.0(3)% is far beyond the theoretical expectation. In order to understand the inconsistency between theory and experiment, we produce the ^{93m}Mo nuclei using the ^{12}C(^{86}Kr,5n) reaction at a beam energy of 559 MeV and transport the reaction residues to a detection station far away from the target area employing a secondary beam line. The isomer depletion is expected to occur during the slowdown process of the ions in the stopping material. In such a low γ-ray background environment, the signature of isomer depletion is not observed, and an upper limit of 2×10^{-5} is estimated for the excitation probability. This is consistent with the theoretical expectation. Our findings shed doubt on the previously reported NEEC phenomenon and highlight the necessity and feasibility of further experimental investigations for reexamining the isomer depletion under low γ-ray background.

7.
Neurobiol Dis ; 155: 105383, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33945876

RESUMO

While several new translational strategies to enhance regrowth of peripheral axons have been identified, combined approaches with different targets are rare. Moreover, few have been studied after a significant delay when growth programs are already well established and regeneration-related protein expression has waned. Here we study two approaches, Rb1 (Retinoblastoma 1) knockdown that targets overall neuron plasticity, and near nerve insulin acting as a growth factor. Both are validated to boost regrowth only at the outset of regeneration. We show that local delivery of Rb1 siRNA alone, with electroporation to an area of prior sciatic nerve injury generated knockdown of Rb1 mRNA in ipsilateral lumbar dorsal root ganglia. While mice treated with Rb1-targeted siRNA, compared with scrambled control siRNA, starting 2 weeks after the onset of regeneration, had only limited behavioural or electrophysiological benefits, they had enhanced reinnervation of epidermal axons. We next confirmed that intrinsic Rb1 knockdown combined with exogenous insulin had dramatic synergistic impacts on the growth patterns of adult sensory neurons studied in vitro, prompting analysis of a combined approach in vivo. Using an identical delayed post-injury protocol, we noted that added insulin not only augmented epidermal reinnervation rendered by Rb1 knockdown alone but also improved indices of mechanical sensation and motor axon recovery. The findings illustrate that peripheral neurons that are well into attempted regrowth retain their responsiveness to both intrinsic and exogenous approaches that improve their recovery. We also identify a novel local approach to manipulate gene expression and outcome in regrowing axons.


Assuntos
Axônios/metabolismo , Regeneração Nervosa/fisiologia , Proteínas de Ligação a Retinoblastoma/deficiência , Neuropatia Ciática/metabolismo , Animais , Axônios/patologia , Técnicas de Silenciamento de Genes/métodos , Masculino , Camundongos , Traumatismos dos Nervos Periféricos/genética , Traumatismos dos Nervos Periféricos/metabolismo , Traumatismos dos Nervos Periféricos/patologia , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Ratos , Proteínas de Ligação a Retinoblastoma/antagonistas & inibidores , Proteínas de Ligação a Retinoblastoma/genética , Neuropatia Ciática/genética , Neuropatia Ciática/patologia
8.
Phys Rev Lett ; 124(10): 102501, 2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-32216444

RESUMO

Interaction cross sections for ^{42-51}Ca on a carbon target at 280 MeV/nucleon have been measured for the first time. The neutron number dependence of derived root-mean-square matter radii shows a significant increase beyond the neutron magic number N=28. Furthermore, this enhancement of matter radii is much larger than that of the previously measured charge radii, indicating a novel growth in neutron skin thickness. A simple examination based on the Fermi-type distribution, and mean field calculations point out that this anomalous enhancement of the nuclear size beyond N=28 results from an enlargement of the core by a sudden increase in the surface diffuseness of the neutron density distribution, which implies the swelling of the bare ^{48}Ca core in Ca isotopes beyond N=28.

9.
Phys Rev Lett ; 124(22): 222504, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32567915

RESUMO

We report the measurement of reaction cross sections (σ_{R}^{ex}) of ^{27,29}F with a carbon target at RIKEN. The unexpectedly large σ_{R}^{ex} and derived matter radius identify ^{29}F as the heaviest two-neutron Borromean halo to date. The halo is attributed to neutrons occupying the 2p_{3/2} orbital, thereby vanishing the shell closure associated with the neutron number N=20. The results are explained by state-of-the-art shell model calculations. Coupled-cluster computations based on effective field theories of the strong nuclear force describe the matter radius of ^{27}F but are challenged for ^{29}F.

10.
Malays J Pathol ; 42(2): 253-257, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32860378

RESUMO

INTRODUCTION: Haemoglobin Constant Spring (Hb CoSp) and Haemoglobin Adana (Hb Adana), are two non-deletion type of α-thalassemia reported in Malaysia. Owing to their structural instability, they cause hemolysis and hyperbilirubinemia. This observational study was part of a large study investigating multiple factors associated with severe neonatal jaundice. In this part we aimed to determine the prevalence of Hb CoSp and Hb Adana and their association with clinically significant neonatal hyperbilirubinemia (SigNH, total serum bilirubin (TSB>290µmol/L)) among jaundiced Malaysian term neonates. MATERIALS AND METHODS: The inclusion criteria were normal term-gestation neonates admitted consecutively for phototherapy. PCR-restriction fragment length polymorphism method was applied on DNA extracted from dry blood spot specimens of each neonate to detect for Hb CoSp and Hb Adana gene. Positive samples were verified by gene sequencing. RESULTS: Of the 1121 neonates recruited (719 SigNH and 402 no-SigNH), heterozygous Hb CoSp gene was detected in only two (0.27%) neonates. Both were SigNH neonates (0.3% or 2/719). No neonate had Hb Adana variant. CONCLUSION: Hb CoSp was not common but could be a risk factor associated with SigNH. No Hb Adana was detected.


Assuntos
Hemoglobinas Anormais/genética , Talassemia alfa/diagnóstico , Bilirrubina/sangue , Feminino , Predisposição Genética para Doença , Humanos , Recém-Nascido , Malásia , Masculino , Fatores de Risco , Análise de Sequência de DNA
11.
Phys Rev Lett ; 121(24): 242501, 2018 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-30608744

RESUMO

The isospin character of p-n pairs at large relative momentum has been observed for the first time in the ^{16}O ground state. A strong population of the J,T=1,0 state and a very weak population of the J,T=0,1 state were observed in the neutron pickup domain of ^{16}O(p,pd) at 392 MeV. This strong isospin dependence at large momentum transfer is not reproduced by the distorted-wave impulse approximation calculations with known spectroscopic amplitudes. The results indicate the presence of high-momentum protons and neutrons induced by the tensor interactions in the ground state of ^{16}O.

12.
Allergy ; 73(8): 1673-1685, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29405354

RESUMO

BACKGROUND: The IL-13 receptor α2 (IL-13Rα2) is a receptor for IL-13 which has conflicting roles in mediating IL-13 responses in the lower airway, with little known about its impact on upper airway diseases. We sought to investigate the expression of IL-13 receptors, IL-13Rα1 and IL-13Rα2, in chronically inflamed nasal epithelium, and explore IL-13-induced signaling pathways in an in vitro model of human nasal epithelial cells (hNECs). METHODS: The protein and mRNA expression levels of IL-13 and its receptors in nasal biopsies of patients with nasal polyps (NP) and healthy controls were evaluated. We investigated goblet cell stimulation with mucus hypersecretion induced by IL-13 (10 ng/mL, 72 hours) treatment in hNECs using a pseudostratified epithelium in air-liquid interface (ALI) culture. RESULTS: There were significant increases in IL-13, IL-13Rα1, and IL-13Rα2 mRNA and protein levels in NP epithelium with healthy controls as baseline. MUC5AC mRNA positively correlated with IL-13Rα2 (r = .5886, P = .002) but not with IL-13Rα1 in primary hNECs. IL-13 treatment resulted in a significant increase in mRNA and protein levels of IL-13Rα2 only in hNECs. IL-13 treatment induced an activation of extracellular signal-regulated kinases (ERK)1/2 and an upregulation of C-JUN, where the IL-13-induced effects on hNECs could be attenuated by ERK1/2 inhibitor (50 µmol/L) or dexamethasone (10-4 -10-7  mol/L) treatment. CONCLUSIONS: IL-13Rα2 has a potential role in IL-13-induced MUC5AC and ciliary changes through ERK1/2 signal pathway in the nasal epithelium. IL-13Rα2 may contribute to airway inflammation and aberrant remodeling which are the main pathological features of CRSwNP.


Assuntos
Subunidade alfa2 de Receptor de Interleucina-13/metabolismo , Interleucina-13/farmacologia , Mucina-5AC/metabolismo , Depuração Mucociliar/efeitos dos fármacos , Mucosa Nasal/imunologia , Pólipos Nasais/imunologia , Rinite/imunologia , Sinusite/imunologia , Adolescente , Adulto , Células Cultivadas , Dexametasona/farmacologia , Feminino , Flavonoides/farmacologia , Glucocorticoides/farmacologia , Humanos , Inflamação/imunologia , Interleucina-13/síntese química , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Muco/efeitos dos fármacos , Muco/metabolismo , Pólipos Nasais/patologia , Inibidores de Proteínas Quinases/farmacologia , Rinite/patologia , Transdução de Sinais , Sinusite/patologia , Estatísticas não Paramétricas , Adulto Jovem
14.
Opt Express ; 25(24): 30626-30635, 2017 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-29221090

RESUMO

The angular surface plasmon mediated fluorescence from a two-dimensional Au nanohole array has been studied by reflectivity spectroscopy and Fourier-space photoluminescence microscopy. By using the rate equation model and temporal coupled mode theory, we determine the momentum-dependent coupling rate of light emitters to (-1,0) Bloch-like surface plasmon polaritons (SPPs) in the first Brillouin zone. The rate increases gradually when the SPPs propagate away from the Γ-X direction and split into two at the Γ-M point where two coupled modes are formed. In addition, both the spectral density-of-states (SDOS) and the plasmonic field energy are found to govern the momentum dependence. We also examine the behavior of the field energy as a function of the SPP propagation direction and it agrees well with the finite-difference time-domain simulations, showing the energy plays a major role in controlling the angular emission intensity. Our results devise a new method in studying the momentum-dependent plasmonic field energy and they are expected to provide insight in directional emission from periodic arrays.

15.
Opt Express ; 25(24): 30611-30625, 2017 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-29221089

RESUMO

By manipulating the relative amplitude and phase between two incoming lights, coherent control of photonic systems can be realized. Here, we show by temporal coupled mode theory and finite-difference time-domain simulation that a coupled system can be actively controlled to exhibit plenty of different spectral, angular, and excitation behaviors. Electromagnetically induced transparency-like and Fano spectral characteristics as well as strong beam steering have been observed. Remarkably, by selectively exciting the coupled modes, we have developed a new approach to determine the complex Hermitian and anti-Hermitian interaction constants. We find the constants are strongly geometric and material dependent and they are of importance in understanding the non-Hermitian physics arising from the dissipative, open coupled system.

16.
Opt Express ; 25(6): 6092-6103, 2017 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-28380964

RESUMO

When light emitters are being placed in close proximity to a plasmonic system, not only the emission but also the excitation can be strongly enhanced and both yield the surface plasmon polariton (SPP) mediated fluorescence enhancement. Here, we combine the rate equation model and coupled mode theory to formulate the excitation rate of light emitters located on a periodic metallic array. The rate is expressed in terms of quantities that can be measured by angle- and polarization-resolved reflectivity and photoluminescence spectroscopy. As a demonstration, we have studied the excitation rate of CdSeTe quantum dots deposited on a 2D Au nanohole array as a function of the propagation direction of the (-1,0) Bloch-like SPPs. At the excitation wavelength of 633 nm, we find the rate remains almost constant at ~44 ps-1 regardless of the propagation direction of SPPs, which move from the Γ-X towards the Γ-M direction in the first Brillouin zone, and the crossing of the (-1,0) and (0,-1) SPPs along the Γ-M direction where two bright and dark modes are formed. The results are supported by the finite-difference time-domain simulations. We conclude the excitation rate is an intrinsic parameter and the enhanced excitation of the quantum dots arises entirely from field enhancement.

17.
Malays J Pathol ; 39(1): 1-15, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28413200

RESUMO

The human oral microbiome has been known to show strong association with various oral diseases including oral cancer. This study attempts to characterize the community variations between normal, oral potentially malignant disorders (OPMD) and cancer associated microbiota using 16S rDNA sequencing. Swab samples were collected from three groups (normal, OPMD and oral cancer) with nine subjects from each group. Bacteria genomic DNA was isolated in which full length 16S rDNA were amplified and used for cloned library sequencing. 16S rDNA sequences were processed and analysed with MOTHUR. A core oral microbiome was identified consisting of Firmicutes, Proteobacteria, Fusobacteria, Bacteroidetes and Actinobacteria at the phylum level while Streptococcus, Veillonella, Gemella, Granulicatella, Neisseria, Haemophilus, Selenomonas, Fusobacterium, Leptotrichia, Prevotella, Porphyromonas and Lachnoanaerobaculum were detected at the genus level. Firmicutes and Streptococcus were the predominant phylum and genus respectively. Potential oral microbiome memberships unique to normal, OPMD and oral cancer oral cavities were also identified. Analysis of Molecular Variance (AMOVA) showed a significant difference between the normal and the cancer associated oral microbiota but not between the OPMD and the other two groups. However, 2D NMDS showed an overlapping of the OPMD associated oral microbiome between the normal and cancer groups. These findings indicated that oral microbes could be potential biomarkers to distinguish between normal, OPMD and cancer subjects.


Assuntos
Bactérias/patogenicidade , Microbiota/efeitos dos fármacos , Neoplasias Bucais/microbiologia , Boca/microbiologia , Neoplasias/microbiologia , Adulto , Idoso , Biomarcadores Tumorais/análise , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Boca/patologia
18.
Opt Express ; 24(12): 12489-500, 2016 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-27410269

RESUMO

We determine the momentum-dependent group velocities of ( ± 1,0) and (0, ± 1) Bloch-like surface plasmon polaritons (SPPs) in two-dimensional Au nanohole array by measuring their propagation lengths and decay lifetimes at different SPP propagation length via angle- and polarization-resolved reflectivity spectroscopy and real- and Fourier-space microscopy. We find the decay length and lifetime, as well as group velocity, are highly dependent on the propagation direction. In particular, close to the Γ-M direction where two SPPs begin to interfere, the group velocity decreases due to the increase of the standing wave character. More importantly, the two SPPs are strongly interacted with each other at the Γ-M direction, resulting in forming the dark and bright modes. We find the group velocity of the dark mode is higher that of the bright mode despite its higher quality factor, or longer decay lifetime. We attribute such difference to the distinct field symmetries of dark and bright modes, yielding different effective indices. While bright mode has fields mostly concentrated at the flat metal region to produce higher effective index and therefore lower velocity, the fields of the dark mode are located near the air hole, resulting in higher velocity.

19.
Phys Rev Lett ; 117(10): 102501, 2016 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-27636470

RESUMO

Proton radii of ^{12-19}C densities derived from first accurate charge changing cross section measurements at 900A MeV with a carbon target are reported. A thick neutron surface evolves from ∼0.5 fm in ^{15}C to ∼1 fm in ^{19}C. The halo radius in ^{19}C is found to be 6.4±0.7 fm as large as ^{11}Li. Ab initio calculations based on chiral nucleon-nucleon and three-nucleon forces reproduce the radii well.

20.
Phys Rev Lett ; 117(20): 202501, 2016 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-27886506

RESUMO

Excitation spectra of ^{11}C are measured in the ^{12}C(p,d) reaction near the η^{'} emission threshold. A proton beam extracted from the synchrotron SIS-18 at GSI with an incident energy of 2.5 GeV impinges on a carbon target. The momenta of deuterons emitted at 0° are precisely measured with the fragment separator (FRS) operated as a spectrometer. In contrast to theoretical predictions on the possible existence of deeply bound η^{'}-mesic states in carbon nuclei, no distinct structures are observed associated with the formation of bound states. The spectra are analyzed to set stringent constraints on the formation cross section and on the hitherto barely known η^{'}-nucleus interaction.

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