The two-photon transition ψ(3686)→γγJ/ψ is studied in a sample of 1.06×10(8) ψ(3686) decays collected by the BESIII detector. The branching fraction is measured to be ...(3.1±0.6(stat)(-1.0)(+0.8)(syst))×10(-4) using J/ψ→e(+)e(-) and J/ψ→μ(+)μ(-) decays, and its upper limit is estimated to be 4.5×10(-4) at the 90% confidence level. This work represents the first measurement of a two-photon transition among charmonium states. The orientation of the ψ(3686) decay plane and the J/ψ polarization in this decay are also studied. In addition, the product branching fractions of sequential E1 transitions ψ(3686)→γχ(cJ) and χ(cJ)→γJ/ψ(J=0,1,2) are reported.
A
bstract
Using
e
+
e
−
annihilation data corresponding to a total integrated luminosity of 6
.
32 fb
−
1
collected at the center-of-mass energies between 4.178 and 4.226 GeV with the BESIII ...detector, we perform an amplitude analysis of the decay
$$ {D}_s^{+} $$
D
s
+
→
K
−
K
+
π
+
π
+
π
−
and determine the relative fractions and phases of different intermediate processes. Absolute branching fraction of
$$ {D}_s^{+} $$
D
s
+
→ K
−
K
+
π
+
π
+
π
−
decay is measured to be (6
.
60
±
0
.
47
stat
.
±
0
.
38
syst
.
)
×
10
−
3
. The dominant intermediate process is
$$ {D}_s^{+} $$
D
s
+
→ a
1
(1260)
+
ϕ, ϕ → K
−
K
+
, a
1
(1260)
+
→ ρπ
+
, ρ → π
+
π
−
, with a branching fraction of (5
.
15
±
0
.
41
stat
.
±
0
.
32
syst
.
)
×
10
−
3
.
The present study was aimed at observing both the damage and change process undergone in lymphatic collectors in obstructive extremity lymphedema. Forty-five patients with obstructive extremity ...lymphedema who had been examined with magnetic resonance lymphangiography (MRL) were enrolled in the study. Among this group, 36 were diagnosed with secondary lymphedema of the lower extremity and 9 exhibited upper extremity lymphedema after mastectomy. Morphological damage as a result of obstruction of collecting lymph vessels was recorded and analyzed. Obvious damage to the lymph vessels was found in all of the 36 lower extremity lymphedema cases with different lengths of history, including vessel disruption in 21 and lymphatic regeneration in 15. Lymphatic damage occurred in the anterior tibial area of the lower leg in almost every case. In 9 cases with upper extremity lymphedema, collecting lymphatic disruption and lymph tracer leakage was seen in multiple patterns. Imaging displayed that ruptured lymph collectors healed spontaneously or regenerated into a segment of the lymphatic network. The present study provided real-time images of collecting lymphatic vessels in obstructive lymphedema. These were seen to have undergone disruption, displayed lymphorrhoea, and/or lymphatic regeneration. In addition, the images suggest that the anterior tibial lymphatic is the weak point of the lymphatic pathway in the lower limb.
CXCL12, also known as stromal cell-derived factor (SDF-1), is a CXC chemokine. Recent reports have shown that CXCL12 might play key roles in a murine model of lupus and in patients with systemic ...lupus erythematosus (SLE). A common variant at position 801 in 3′-untranslated region in CXCL12 gene (designated CXCL12-3′G801A) has been reported in association with autoimmune diseases, such as type 1 diabetes and systemic sclerosis. We investigated the influence of CXCL12-3′G801A polymorphism on susceptibility to SLE by genotyping this single nucleotide polymorphism in 422 SLE patients and 374 healthy controls. The frequency of G/G homozygote was observed in 60.0% of SLE patients and in 52.7% of healthy individuals (χ2 = 4.275, p = 0.039). Compared with patients with G/A and A/A genotype, SLE patients with G/G genotype were also more prone to developing photosensitivity (χ2 = 6.778, p = 0.034), renal damage (χ2 = 6.388, p = 0.041) and to producing antibodies against nucleosomes (χ2 = 8.341, p = 0.015). Moreover, the plasma level of CXCL12α was also significantly increased in patients with G/G homozygote than in healthy controls carrying the same genotype (4067.0 ± 1092.3) pg/ml vs. (3278.5 ± 547.4) pg/ml, p = 0.002. Our results suggest that polymorphism in CXCL12-3′G801A might be a genetic risk factor for developing SLE. The association of G/G homozygote with nephritis and skin damage developed in SLE patients might be due to its effects upon the production of auto-antibodies and CXCL12 protein.
In nanocrystalline (nc) metals, it is still not clear how local grain boundary (GB) structures accommodate GB migration at atomic scales and what dominates the motion of atoms at the inherently ...unstable GB front. Here, we report the adjustment of the local GB structures at atomic scales during self-driven GB migration, simultaneously involving GB dissociation, partial dislocation emission from GB, and faceting/defaceting in the nc Cu. Furthermore, we reveal that the fundamental of GB migration ability is closely related to the local structure, i.e. the GB segment consisting of “hybrid” structural units and delocalized GB dislocations is relatively unstable.
Using a sample of 1.31×109 J/ψ events collected with the BESIII detector, we perform a search for the rare decay η′→4π0 via J/ψ→γη′. No significant η′ signal is observed in the 4π0 invariant mass ...spectrum. With a Bayesian approach, the upper limit on the branching fraction is determined to be B(η′→4π0)<4.94×10−5 at the 90% confidence level, which is a factor of 6 smaller than the previous experimental limit.
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