A
bstract
The Born cross sections of the
e
+
e
−
→ D
*+
D
*
−
and
e
+
e
−
→ D
*+
D
−
processes are measured using
e
+
e
−
collision data collected with the BESIII experiment at center-of-mass ...energies from 4.085 to 4.600 GeV, corresponding to an integrated luminosity of 15
.
7 fb
−
1
. The results are consistent with and more precise than the previous measurements by the Belle, Babar and CLEO collaborations. The measurements are essential for understanding the nature of vector charmonium and charmonium-like states.
The spin and parity of the Z_{c}(3900)^{±} state are determined to be J^{P}=1^{+} with a statistical significance larger than 7σ over other quantum numbers in a partial wave analysis of the process ...e^{+}e^{-}→π^{+}π^{-}J/ψ. We use a data sample of 1.92 fb^{-1} accumulated at sqrts=4.23 and 4.26 GeV with the BESIII experiment. When parametrizing the Z_{c}(3900)^{±} with a Flatté-like formula, we determine its pole mass M_{pole}=(3881.2±4.2_{stat}±52.7_{syst}) MeV/c^{2} and pole width Γ_{pole}=(51.8±4.6_{stat}±36.0_{syst}) MeV. We also measure cross sections for the process e^{+}e^{-}→Z_{c}(3900)^{+}π^{-}+c.c.→J/ψπ^{+}π^{-} and determine an upper limit at the 90% confidence level for the process e^{+}e^{-}→Z_{c}(4020)^{+}π^{-}+c.c.→J/ψπ^{+}π^{-}.
AIMTo investigate the performance of a generative adversarial network (GAN) model for staging liver fibrosis and its radiomics-based nomogram for predicting cirrhosis. MATERIALS AND METHODSThis ...two-centre retrospective study included 434 patients for whom input data of ultrasound images and histopathological data (obtained within 1 month of ultrasound examinations) were assigned to the training cohort (249 patients), the internal cohort (92 patients), and the external (93 patients) cohort. A data augmentation method based on a GAN model was used. The discriminative performance was evaluated for classifying fibrosis of S4 and ≥S3. Deep-learning radiomics features were extracted for the prediction of cirrhosis (S4). To perform feature reduction and selection, the least absolute shrinkage and selection operator (LASSO) algorithm was applied. Radiomics scores, along with clinical factors, were incorporated into a nomogram using multivariable logistic regression analysis. The performance of the models was estimated with respect to discrimination power, calibration, and clinical benefits. RESULTSThe areas under the receiver operating characteristic curve (AUCs) values of the GAN were 0.832/0.762 (≥S3), and 0.867/0.835 (S4) for internal/external test sets, respectively. The radiomics nomogram that intergrated radiomics scores and clinical factors showed good calibration and discrimination ability of 0.922 (AUC) in the training dataset, 0.896 in the internal dataset, and 0.861 in the external dataset. Decision curve analysis (DCA) demonstrated that the nomogram outperformed radiologist and haematological indices in terms of the most clinical benefits. CONCLUSIONSThe GAN model could be applied to discriminate fibrosis stages, and a favourable predictive accuracy for diagnosing cirrhosis was achieved using a deep-learning radiomics nomogram.
The cross sections of e^{+}e^{-}→π^{+}π^{-}h_{c} at center-of-mass energies from 3.896 to 4.600 GeV are measured using data samples collected with the BESIII detector operating at the Beijing ...Electron Positron Collider. The cross sections are found to be of the same order of magnitude as those of e^{+}e^{-}→π^{+}π^{-}J/ψ and e^{+}e^{-}→π^{+}π^{-}ψ(2S), but the line shape is inconsistent with the Y states observed in the latter two modes. Two structures are observed in the e^{+}e^{-}→π^{+}π^{-}h_{c} cross sections around 4.22 and 4.39 GeV/c^{2}, which we call Y(4220) and Y(4390), respectively. A fit with a coherent sum of two Breit-Wigner functions results in a mass of (4218.4_{-4.5}^{+5.5}±0.9) MeV/c^{2} and a width of (66.0_{-8.3}^{+12.3}±0.4) MeV for the Y(4220), and a mass of (4391.5_{-6.8}^{+6.3}±1.0) MeV/c^{2} and a width of (139.5_{-20.6}^{+16.2}±0.6) MeV for the Y(4390), where the first uncertainties are statistical and the second ones systematic. The statistical significance of Y(4220) and Y(4390) is 10σ over one structure assumption.
A
bstract
Using
e
+
e
−
collision data corresponding to a total integrated luminosity of 12.9 fb
−
1
collected with the BESIII detector at the BEPCII collider, the exclusive Born cross sections and ...the effective form factors of the reaction
e
+
e
−
→
Ξ
−
Ξ
¯
+
are measured via the single baryon-tag method at 23 center-of-mass energies between 3.510 and 4.843 GeV. Evidence for the decay
ψ
3770
→
Ξ
−
Ξ
¯
+
is observed with a significance of 4.5
σ
by analyzing the measured cross sections together with earlier BESIII results. For the other charmonium(-like) states
ψ
(4040),
ψ
(4160),
Y
(4230),
Y
(4360),
ψ
(4415), and
Y
(4660), no significant signal of their decay to
Ξ
−
Ξ
¯
+
is found. For these states, upper limits of the products of the branching fraction and the electronic partial width at the 90% confidence level are provided.
Observation of e+e- → γX(3872) at BESIII Achasov, M N; Albayrak, O; Ambrose, D J ...
Physical review letters,
2014-Mar-07, Letnik:
112, Številka:
9
Journal Article
Recenzirano
Odprti dostop
With data samples collected with the BESIII detector operating at the BEPCII storage ring at center-of-mass energies from 4.009 to 4.420 GeV, the process e+e-→ γX(3872) is observed for the first time ...with a statistical significance of 6.3σ. The measured mass of the X(3872) is (3871.9 ± 0.7s tat ± 0.2 syst) MeV/c(2), in agreement with previous measurements. Measurements of the product of the cross section σe+e- → γX(3872) and the branching fraction BX(3872)→π+π-J/ψ at center-of-mass energies 4.009, 4.229, 4.260, and 4.360 GeV are reported. Our measurements are consistent with expectations for the radiative transition process Y(4260) → γX(3872).
Clostridioides difficile is considered an urgent threat to human health by the US Centers for Disease Control and Prevention. In recent years, C. difficile has been reported increasingly as a cause ...of gastrointestinal disease in children, and the prevalence of hospital-acquired C. difficile infection and community-acquired CDI in children is increasing.
To perform a systematic review and meta-analysis of risk factors for CDI in children.
MEDLINE/PubMed, EMBASE, Web of Science, Scopus, OVID, China National Knowledge Infrastructure, Wanfang (Chinese), SinoMed (Chinese) and Weipu (Chinese) were searched from inception to 12th January 2022. Observational studies (cohort, case–control and cross-sectional) on CDI in children were included in the analysis. Data were pooled using a fixed or random-effects model, and odds ratios (OR) were calculated.
In total, 25 observational studies were included in the analysis. Prior antibiotic exposure OR 1.93, 95% confidence interval (CI) 1.25–2.97, prolonged hospitalization (OR 14.68, 95% CI 13.24–16.28), history of hospitalization (OR 3.67, 95% CI 1.91–7.06), gastric acid suppressants (OR 1.96, 95% CI 1.41–2.73), male gender (OR 1.18, 95% CI 1.05–1.32), neoplastic disease (OR 3.40, 95% CI, 2.85–4.07), immunodeficiency (OR 4.18, 95% CI 3.25–5.37), solid organ transplantation (OR 4.56, 95% CI 3.95–5.27) and enteral feeding (OR 2.21, 95% CI 1.05–4.62) were associated with increased risk of CDI.
This systematic review and meta-analysis provides further evidence for the susceptibility factors of CDI to improve clinicians' awareness of CDI, and prevent C. difficile-associated diarrhoea in children.
A
bstract
Using data samples with an integrated luminosity of 19 fb
−
1
at twenty-eight center-of-mass energies from 3.872 GeV to 4.700 GeV collected with the BESIII detector at the BEPCII ...electron-positron collider, the process
e
+
e
−
→
ηπ
+
π
−
and the intermediate process
e
+
e
−
→
ηρ
0
are studied for the first time. The Born cross sections are measured. No significant resonance structure is observed in the cross section lineshape.
A survey of C
2
H
N
= 1 − 0 and N
2
H
+
J
= 1 − 0 toward
Planck
Galactic cold clumps (PGCCs) was performed using the Purple Mountain Observatory’s 13.7 m telescope. C
2
H and N
2
H
+
were chosen to ...study the chemical evolutionary states of PGCCs. Among 121 observed molecular cores associated with PGCCs, 71 and 58 are detected with C
2
H
N
= 1 − 0 and N
2
H
+
J
= 1 − 0, respectively. The detected lines of most sources can be fitted with a single component with compatible
V
LSR
and line widths, which confirms that these PGCC cores are very cold (with gas temperatures 9–21 K) and quiescent while still dominanted by turbulence. The ratio between the column densities of C
2
H and N
2
H
+
(
N
(C
2
H)/
N
(N
2
H
+
)) is found to be a good tracer for the evolutionary states of PGCC cores. Gas-grain chemical model can reproduce the decreasing trend of
N
(C
2
H)/
N
(N
2
H
+
) as a function of time. The cores with the lowest abundances of N
2
H
+
(
X
N
2
H
+
< 10
−10
) are the youngest, and have nearly constant abundances of C
2
H. In evolved cores with
X
N
2
H
+
~10
−9
, abundances of C
2
H drop quickly as the exhaustion of carbon atoms. Although these PGCC cores are in different evolutionary states, they are all quite young (< 5 × 10
5
yr) with
N
(C
2
H) >
N
(N
2
H
+
). Mapping observations are carried out toward 20 PGCC cores. The PGCC cores in Cepheus have lower
N
(C
2
H)/
N
(N
2
H
+
) and larger line widths compared with those in Taurus. This implies that PGCC cores in Taurus are less chemically evolved than those in Cepheus.
A
bstract
A partial wave analysis on the process
e
+
e
−
→
ωπ
+
π
−
is performed using 647 pb
−
1
of data sample collected by using the BESIII detector operating at the BEPCII storage ring at ...center-of-mass (c.m.) energies from 2.000 GeV to 3.080 GeV. The Born cross section of the
e
+
e
−
→
ωπ
+
π
−
process is measured, with precision improved by a factor of 3 compared to that of previous studies. A structure near 2.25 GeV is observed in the energy-dependent cross sections of
e
+
e
−
→
ωπ
+
π
−
and
ωπ
0
π
0
with a statistical significance of 7.6
σ
, and its determined mass and width are 2232 ± 19 ± 27 MeV
/c
2
and 93 ± 53 ± 20 MeV, respectively, where the first and second uncertainties are statistical and systematic, respectively. By analyzing the cross sections of subprocesses
e
+
e
−
→
ωf
0
(500),
ωf
0
(980),
ωf
0
(1370),
ωf
2
(1270), and
b
1
(1235)
π
, a structure, with mass M = 2200 ± 11 ± 17 MeV/
c
2
and width Γ = 74 ± 20 ± 24 MeV, is observed with a combined statistical significance of 7.9
σ
. The measured resonance parameters will help to reveal the nature of vector states around 2.25 GeV.
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