29 research outputs found

    Geometric and Volumetric Measurements of Orbital Structures in CT Scans in Thyroid Eye Disease Classification

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    This study examines the usefulness of both geometric and volumetric measurements of orbital soft tissues on CT scans to provide quantitative diagnostic guidance in image reading of thyroid eye disease (TED). Computed tomography (CT) images were obtained from 92 orbits and were classified as impaired motility (TED-IM) and normal motility (TED-NM). The TED-IM group was further divided into dysthyroid optic neuropathy (DON) and non-DON groups. There were 5 volumetric, 2 angular, and 3 ratio parameter measurements acquired from CT images to examine their feasibility in TED classification. We found that the mean volumes of extraocular muscle and retroorbital fat and their ratio to the orbital volume were significantly different between the two motility groups. The mean ratio of extraocular muscle volume in orbital apex and orbital apex volume (EMV-OA/OAV) was significantly larger in DON than non-DON patients (p < 0.05). The population distribution among TED-NM, non-DON, and DON groups significantly varied for different angles between the optic nerve and medial rectus and lateral rectus. In conclusion, geometric and volumetric measurements using CT scans help to quantitatively classify TED

    Retrospective Case Analysis of Transnasal Endoscopic Resection of Benign Orbital Apex Tumors: Some Thoughts on Transnasal Endoscopic Surgery

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    Purpose. To deeply discuss the patient selection, surgical planning, surgical techniques, and the therapeutic challenge for endoscopic transnasal resection of benign orbital apex tumors (OATs). Methods. We retrospectively analyzed the cases of 18 patients (18 eyes) with orbital apex cavernous hemangioma (OACH) who underwent endoscopic transnasal approach for resection of the tumor in Zhongshan Ophthalmic Center from March 2016 to May 2020. At each follow-up visit, the patients underwent measurement of their best-corrected visual acuity (BCVA), slit-lamp examination, indirect ophthalmoscopy, and visual field testing. Results. There were 18 patients, 7 males and 11 females, with a mean age of 49.9 ± 12.6 years (range: 26 to 70 years). All 18 patients had unilateral tumors. Among the 18 cases, 13 were located in the right orbit and 5 were located in the left orbit. Sixteen patients underwent purely endoscopic transnasal surgery, and the other 2 patients underwent an endoscopic transnasal approach combined with a transcutaneous or transconjunctival surgical approach. Fourteen patients’ OACHs were removed completely, 1 patient’s OACH was partly removed, and 3 patients underwent pure decompression of the optic nerve. Fourteen patients gained improved or stable BCVA after surgery. Three patients showed postoperative vision decline, and 1 patient had no light perception after surgery. Conclusions. Endoscopic surgery is an effective surgical technique for the treatment of benign tumors in the orbital apex. It is necessary to strictly select patients and fully evaluate the benefits and risks of tumor completely or partly removed

    Observation of D → a₀(980)π in the decays D⁰ → π⁺π^(−)η and D⁺ → π⁺π⁰η

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    We report the first amplitude analysis of the decays D0→π+π−η and D+→π+π0η using a data sample taken with the BESIII detector at the center-of-mass energy of 3.773 GeV, corresponding to an integrated luminosity of 7.9 fb−1. The contribution from the process D0(+)→a0(980)+π−(0) is significantly larger than the D0(+)→a0(980)−(0)π+ contribution. The ratios B(D0→a0(980)+π−)/B(D0→a0(980)−π+) and B(D+→a0(980)+π0)/B(D+→a0(980)0π+) are measured to be 7.5+2.5−0.8stat.±1.7syst. and 2.6±0.6stat.±0.3syst., respectively. The measured D0 ratio disagrees with the theoretical predictions by orders of magnitudes, thus implying a substantial contribution from final-state interactions

    Search for di-photon decays of an axion-like particle in radiative decays of J/psi

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    We search for the di-photon decay of a light pseudoscalar axion-like particle, a, in radiative decays of the J/ψ, using 10 billion J/ψ events collected with the BESIII detector. We find no evidence of a narrow resonance and set upper limits at the 95% confidence level on the product branching fraction B(J/ψ→γa)×B(a→γγ) and the axion-like particle photon coupling constant gaγγ in the ranges of (3.6−49.8)×10−8 and (2.2−103.8)×10−4 GeV−1, respectively, for 0.18≤ma≤2.85 GeV/c2. These are the most stringent limits to date in this mass region

    Measurement of e+e− → ηJ/ψ cross section from √s= 3.808 GeV to 4.951 GeV

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    Using data samples with an integrated luminosity of 22.42  fb−1 collected by the BESIII detector operating at the BEPCII storage ring, we measure the cross sections of the +⁢−→⁢/ process at center-of-mass energies from 3.808 to 4.951 GeV. Three structures are observed in the line shape of the measured cross sections. A maximum-likelihood fit with ⁡(4040), two additional resonances, and a nonresonant component are performed. The mass and width of the first additional state are (4219.7±2.5±4.5)  MeV/2 and (80.7±4.4±1.4)  MeV, respectively, consistent with the ⁡(4230). For the second state, the mass and width are (4386±13±17)  MeV/2 and (177±32±13)  MeV, respectively, consistent with the ⁡(4360). The first uncertainties are statistical, and the second ones are systematic. The statistical significance of ⁡(4040) is 8.0⁢ and those for ⁡(4230) and ⁡(4360) are more than 10.0⁢

    Measurement of e+e− → ηJ/ψ Cross Section from √s= 3.808 GeV to 4.951 GeV

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    Using data samples with an integrated luminosity of 22.42 fb−1 collected by the BESIII detector operating at the BEPCII storage ring, we measure the cross sections of the e^{+}e^{-}\rightarrow\etaJ/\psi process at center-of-mass energies from 3.808 to 4.951 GeV. Three structures are observed in the line shape of the measured cross sections. A maximum-likelihood fit with ψ(4040), two additional resonances, and a non-resonant component is performed. The mass and width of the first additional state are (4219.7±2.5±4.5)MeV/c2 and (80.7±4.4±1.4)MeV, respectively, consistent with the ψ(4230). For the second state, the mass and width are (4386±13±17)MeV/c2 and (177±32±13)MeV, respectively, consistent with the ψ(4360). The first uncertainties are statistical and the second ones are systematic. The statistical significance of ψ(4040) is 8.0σ and those for ψ(4230) and ψ(4360) are more than 10.0σ

    Search for the rare decays D_(s)⁺ → h⁺(h⁰)e⁺e^(−)

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    Using 7.33~fb−1 of e+e− collision data collected by the BESIII detector at center-of-mass energies in the range of s√=4.128−4.226~GeV, we search for the rare decays D+s→h+(h0)e+e−, where h represents a kaon or pion. By requiring the e+e− invariant mass to be consistent with a ϕ(1020), 0.98<M(e+e−)<1.04 ~GeV/c2, the decay D+s→π+ϕ,ϕ→e+e− is observed with a statistical significance of 7.8σ, and evidence for the decay D+s→ρ+ϕ,ϕ→e+e− is found for the first time with a statistical significance of 4.4σ. The decay branching fractions are measured to be B(D+s→π+ϕ,ϕ→e+e−)=(1.17+0.23−0.21±0.03)×10−5, and B(D+s→ρ+ϕ,ϕ→e+e−)=(2.44+0.67−0.62±0.16)×10−5, where the first uncertainties are statistical and the second systematic. No significant signal for the three four-body decays of D+s→π+π0e+e−, D+s→K+π0e+e−, and D+s→K0Sπ+e+e− is observed. For D+s→π+π0e+e−, the ϕ mass region is vetoed to minimize the long-distance effects. The 90% confidence level upper limits set on the branching fractions of these decays are in the range of (7.0−8.1)×10−5

    Study of the decay J/ψ → φπ0η

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    Based on (10.09±0.04)×109 J/ψ events collected with the BESIII detector operating at the BEPCII collider, a partial wave analysis of the decay J/ψ→ϕπ0η is performed. We observe for the first time two new structures on the ϕη invariant mass distribution, with statistical significances of 24.0σ and 16.9σ; the first with JPC = 1+−, mass M = (1911 ± 6 (stat.) ± 14 (sys.))~MeV/c2, and width Γ= (149 ± 12 (stat.) ± 23 (sys.))~MeV, the second with JPC = 1−−, mass M = (1996 ± 11 (stat.) ± 30 (sys.))~MeV/c2, and width Γ = (148 ± 16 (stat.) ± 66 (sys.))~MeV. These measurements provide important input for the strangeonium spectrum. In addition, the f0(980)−a0(980)0 mixing signal in J/ψ→ϕf0(980)→ϕa0(980)0 and the corresponding electromagnetic decay J/ψ→ϕa0(980)0 are measured with improved precision, providing crucial information to understand the nature of a0(980)0 and f0(980)

    First observation of the decay Λ+c → nK0Sπ+π0

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    Based on 4.5 fb−1 of e+e− collision data accumulated at center-of-mass energies between 4599.53 MeV and 4698.82 MeV with the BESIII detector, the decay Λ+c→nK0Sπ+π0 is observed for the first time with a significance of 9.2σ. The branching fraction is measured to be (0.85±0.13±0.03)%, where the first uncertainty is statistical and the second systematic, which differs from the theoretical prediction based on isospin by 4.4σ. This indicates that there may be resonant contributions or some unknown dynamics in this decay

    Search for e⁺e^(−) → η′ψ(2S) at center-of-mass energies from 4.66 to 4.95 GeV

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    Using data samples with an integrated luminosity of 4.67 fb−1 collected by the BESIII detector operating at the BEPCII collider, we search for the process e+e−→η′ψ(2S) at center-of-mass energies from 4.66 to 4.95 GeV. No significant signal is observed, and upper limits for the Born cross sections σB(e+e−→η′ψ(2S)) at the 90\% confidence level are determined
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