Measurement of the Cross Section for e^{+}e^{-}→Hadrons at Energies from 2.2324 to 3.6710 GeV

Based on electron-positron collision data collected with the BESIII detector operating at the Beijing Electron-Positron Collider II storage rings, the value of R≡σ(e^{+}e^{-}→hadrons)/σ(e^{+}e^{-}→μ^{+}μ^{-}) is measured at 14 center-of-mass energies from 2.2324 to 3.6710 GeV. The resulting uncertainties are less than 3.0% and are dominated by systematic uncertainties.

Preoperative MRI of breast squamous cell carcinoma: diagnostic value of distinguishing between two subtypes

AIM

To retrospectively analyse the clinical and MRI data of primary squamous cell carcinoma (SCC), particularly pure squamous cell carcinoma (PSCC) and mixed squamous cell carcinoma (MSCC).

MATERIALS AND METHODS

The MRI data and clinicopathological characteristics of 20 patients with histopathologically confirmed SCC of the breast, including eight PSCC patients and 12 MSCC patients, from multiple centres between January 2013 and December 2020 were analysed retrospectively.

RESULTS

Nine of 12 patients in the MSCC group showed hyperintensity on T1-weighted imaging (WI), while this feature was not observed in the PSCC group (p=0.001). Most of the PSCC group showed rim enhancement, whereas most of the MSCC group showed heterogeneous enhancement (p=0.007). In addition, there was no significant difference in the thickness of the rim enhancement and the percentage of necrotic components in the tumours between the two types of SCCs of the breast (p=0.545 and p=0.662, respectively). Four patients (4/12) in the MSCC group had sentinel lymph node metastasis, while only one patient (1/8) in the PSCC group showed lymph node metastasis (p=0.603). Metastatic disease occurred in 25% of patients with PSCC and in approximately 41.7% of patients with MSCC.

CONCLUSION

The signal on T1WI and internal enhancement characteristics were the key features for differentiating PSCC and MSCC. Therefore, MRI phenotypes may provide additional information for the pathological classification of breast SCC.

Phenotypic heterogeneity in persisters: a novel 'hunker' theory of persistence

Persistence has been linked to treatment failure since its discovery over 70 years ago and understanding formation, nature and survival of this key antibiotic refractory subpopulation is crucial to enhancing treatment success and combatting the threat of antimicrobial resistance (AMR). The term 'persistence' is often used interchangeably with other terms such as tolerance or dormancy. In this review we focus on 'antibiotic persistence' which we broadly define as a feature of a subpopulation of bacterial cells that possesses the non-heritable character of surviving exposure to one or more antibiotics; and persisters as cells that possess this characteristic. We discuss novel molecular mechanisms involved in persister cell formation, as well as environmental factors which can contribute to increased antibiotic persistence in vivo, highlighting recent developments advanced by single-cell studies. We also aim to provide a comprehensive model of persistence, the 'hunker' theory which is grounded in intrinsic heterogeneity of bacterial populations and a myriad of 'hunkering down' mechanisms which can contribute to antibiotic survival of the persister subpopulation. Finally, we discuss antibiotic persistence as a 'stepping-stone' to AMR and stress the urgent need to develop effective anti-persister treatment regimes to treat this highly clinically relevant bacterial sub-population.

First Measurement of Polarizations in the Decay D^{0}→ωφ

Using a data sample corresponding to an integrated luminosity of 2.93  fb^{-1} collected at a center-of-mass energy sqrt[s]=3.773  GeV by the BESIII detector, the decay D^{0}→ωϕ is observed for the first time. The branching fraction is measured to be (6.48±0.96±0.40)×10^{-4} with a significance of 6.3σ, where the first and second uncertainties are statistical and systematic, respectively. An angular analysis reveals that the ϕ and ω mesons from the D^{0}→ωϕ decay are transversely polarized. The 95% confidence level upper limit on longitudinal polarization fraction is set to be less than 0.24, which is inconsistent with current theoretical expectations and challenges our understanding of the underlying dynamics in charm meson decays.

An examination of maximum legal application rates of dairy processing and associated STRUBIAS fertilising products in agriculture

The dairy industry produces vast quantities of dairy processing sludge (DPS), which can be processed further to develop second generation products such as struvite, biochars and ashes (collectively known as STRUBIAS). These bio-based fertilizers have heterogeneous nutrient and metal contents, resulting in a range of possible application rates. To avoid nutrient losses to water or bioaccumulation of metals in soil or crops, it is important that rates applied to land are safe and adhere to the maximum legal application rates similar to inorganic fertilizers. This study collected and analysed nutrient and metal content of all major DPS (n = 84) and DPS-derived STRUBIAS products (n = 10), and created an application calculator in MS Excel™ to provide guidance on maximum legal application rates for ryegrass and spring wheat across plant available phosphorus (P) deficient soil to P-excess soil. The sample analysis showed that raw DPS and DPS-derived STRUBIAS have high P contents ranging from 10.1 to 122 g kg^-1. Nitrogen (N) in DPS was high, whereas N concentrations decreased in thermo-chemical STRUBIAS products (chars and ash) due to the high temperatures used in their formation. The heavy metal content of DPS and DPS-derived STRUBIAS was significantly lower than the EU imposed limits. Using the calculator, application rates of DPS and DPS-derived STRUBIAS materials (dry weight) ranged from 0 to 4.0 tonnes ha^-1 y^-1 for ryegrass and 0-4.5 tonnes ha^-1 y^-1 for spring wheat. The estimated heavy metal ingestion to soil annually by the application of the DPS and DPS-derived STRUBIAS products was lower than the EU guideline on soil metal accumulation. The calculator is adaptable for any bio-based fertilizer, soil and crop type, and future work should continue to characterise and incorporate new DPS and DPS-derived STRUBIAS products into the database presented in this paper. In addition, safe application rates pertaining to other regulated pollutants or emerging contaminants that may be identified in these products should be included. The fertilizer replacement value of these products, taken from long-term field studies, should be factored into application rates.

Measurement of the Sixth-Order Cumulant of Net-Proton Multiplicity Distributions in Au+Au Collisions at sqrt[s_{NN}]=27, 54.4, and 200 GeV at RHIC

According to first-principle lattice QCD calculations, the transition from quark-gluon plasma to hadronic matter is a smooth crossover in the region μ_{B}≤T_{c}. In this range the ratio, C_{6}/C_{2}, of net-baryon distributions are predicted to be negative. In this Letter, we report the first measurement of the midrapidity net-proton C_{6}/C_{2} from 27, 54.4, and 200 GeV Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC). The dependence on collision centrality and kinematic acceptance in (p_{T}, y) are analyzed. While for 27 and 54.4 GeV collisions the C_{6}/C_{2} values are close to zero within uncertainties, it is observed that for 200 GeV collisions, the C_{6}/C_{2} ratio becomes progressively negative from peripheral to central collisions. Transport model calculations without critical dynamics predict mostly positive values except for the most central collisions within uncertainties. These observations seem to favor a smooth crossover in the high-energy nuclear collisions at top RHIC energy.

≠Risk of breast implant removal after one- versus two-stage breast reconstructive surgery

BACKGROUND

To date, both one- and two-stage techniques are used in immediate 'implant-based breast reconstruction' (IBBR) after mastectomy. Because it is still unknown what technique offers the best clinical outcomes, a multicenter retrospective study was conducted to compare both breast reconstruction techniques.

METHODS

All patients, who underwent a mastectomy followed by immediate one- or two-stage IBBR during 2010 - 2016 were included. Our primary outcome measure was explantation of the 'tissue expander' (TE) and/ or implants within 60 days after breast reconstruction. Secondary outcomes were overall complication rate and secondary corrections.

FINDINGS

Among a total of 383 women, TE/ implant explantation rate was higher in one-stage (19.9%) than in two-stage (11.3%) treated patients (p = 0.082). Overall complication rate (35.7% and 19.9% respectively, p = 0.008) and secondary corrections (29.8% and 20.3% respectively, p = 0.156) were also higher in one-stage compared to two-stage IBBR respectively. However, explantation (OR = 1.55; 95%CI = 0.67-3.58, p = 0.301) and complication (OR = 1.85; 95%CI = 0.92-3.37, p = 0.084) rates were comparable in one- and two-stage IBBR in our stratified multivariate logistic regression analyses, when controlling for history of smoking, nipple-sparing mastectomy, neoadjuvant radiation therapy, and removed breast tissue weight. A remarkable outcome in this study is that women treated with prophylactic surgery were more likely to have an explantation of the TE/ implant after a one-stage IBBR (OR = 4.49; 95%CI = 1.10-18.3, p = 0.037) than two-stage IBBR. In contrast, no association between type of IBBR and risk of TE/implants removal was found among women with a therapeutic mastectomy (OR = 0.82; 95%CI = 0.24-2.79, p =  = 0.74).

CONCLUSION

One- and two-stage IBBR showed a comparable explantation and complication rate in our retrospective study. In one-stage IBBR more secondary corrections were detected. In addition, women who have to decide on a prophylactic mastectomy should be aware of a significantly higher risk of explantation of their implant after one-stage IBBR.

Grain size dependent high-pressure elastic properties of ultrafine micro/nanocrystalline grossular

We have performed sound velocity and unit cell volume measurements of three synthetic, ultrafine micro/nanocrystalline grossular samples up to 50 GPa using Brillouin spectroscopy and synchrotron X-ray diffraction. The samples are characterized by average grain sizes of 90 nm, 93 nm and 179 nm (hereinafter referred to as samples Gr90, Gr93, and Gr179, respectively). The experimentally determined sound velocities and elastic properties of Gr179 sample are comparable with previous measurements, but slightly higher than those of Gr90 and Gr93 under ambient conditions. However, the differences diminish with increasing pressure, and the velocity crossover eventually takes place at approximately 20-30 GPa. The X-ray diffraction peaks of the ultrafine micro/nanocrystalline grossular samples significantly broaden between 15-40 GPa, especially for Gr179. The velocity or elasticity crossover observed at pressures over 30 GPa might be explained by different grain size reduction and/or inhomogeneous strain within the individual grains for the three grossular samples, which is supported by both the pressure-induced peak broadening observed in the X-ray diffraction experiments and transmission electron microscopy observations. The elastic behavior of ultrafine micro/nanocrystalline silicates, in this case, grossular, is both grain size and pressure dependent.

[A comparative study on the difference of gut microbiota and its biomarkers between patients with pulmonary tuberculosis and healthy controls]

Objective: To analyze the differences in the composition and abundance of gut microbiota between patients with active pulmonary tuberculosis and healthy controls, and to identify the specific bacteria as biomarkers to distinguish between the two groups. Methods: Patients with active pulmonary tuberculosis treated in three municipal designated tuberculosis medical institutions in Sichuan, Jiangsu and Shanghai from September 2017 to September 2019 were selected as the case group (n=88), and the healthy people without a history of tuberculosis from the same regions were recruited as the control group (n=62). The fecal samples of the two groups were detected by 16S rRNA gene sequencing, and the differences of gut microbiota diversity, community composition and relative abundance at phylum and genus level from the two groups were analyzed. The random forest method was used to construct a predictive model to assess whether the specific bacterial flora could be used as biomarkers to distinguish tuberculosis patients from healthy people. Results: The alpha diversity analysis showed that the species richness and evenness of gut microbiota in tuberculosis patients were significantly lower than those in healthy controls (P<0.001). There was a statistically significant difference in the composition of microbiota between the two groups (Bray-Curtis distance, P<0.001). In the gut microbiota of tuberculosis patients, opportunistic pathogens were relatively enriched, while some of the beneficial bacteria that can produce short-chain fatty acids were less abundant. The discrimination accuracy of the random forest model composed of Lachnospira, Lachnospiraceae ND3007 group and Roseburia was 76.67%, with area under the curve (AUC) being 75.29% (95%CI: 0.661-0.845). Conclusion: There were differences in gut microbiota between patients with active pulmonary tuberculosis and healthy people, and specific bacterial flora showed the potential to be used as biomarkers to distinguish between the two groups.

[Clinical and genetic features of seven children with MYH9-related disease]

Objective: To summarize and analyze of the clinical and genetic characteristics of children with nonmuscle myosin heavy chain 9 (MYH9)-related disease (MYH9-RD). Methods: To screen the patients who were first diagnosed as "chronic/refractory immune thrombocytopenia (ITP) " from April 2016 to May 2019 in Beijing Children's Hospital by genetic and clinical examinations, then the clinical manifestation, laboratory examination and genetics results of 7 children diagnosed with MYH9-RD were collected and summarized retrospectively. Results: Among 7 children diagnosed with MYH9-RD, 3 were males and 4 females. The age of onset was 1.25 (0.41-6.16) years. The course of disease was 2.16 (0.41-8.59) years. The automatic platelet count was (9 (5-30))×10⁹/L. All the cases were found with giant platelets under microscope,and the manual platelet count was (70 (30-100))×10⁹/L. Four cases had skin hemorrhage or epistaxis and 3 cases had no bleeding. All 7 patients had received first-or second-line therapy of ITP, of whom 1 case received splenic embolization, and all the treatments mentioned above were ineffective. Finally, it was confirmed that all 7 patients had heterozygous missense mutations of MYH9 gene by next generation sequencing (NGS), including 2 pedigrees and 5 sporadic cases. Four sporadic mutations occurred in N-terminal globular head domain (HD), and 1 sporadic case with p.D1424N mutations occurred in the C-terminal tail domain (TD). One of the pedigrees also had p.D1424N mutation. The other familial case had a novel variant with one missense variant p.A44D caused by the c.131C>A transition. One of the two p.R702 mutations had kidney damage, and several relatives of the new p.A44D mutations had deafness. Conclusions: In this study, the spontaneous mutations of seven MYH9-RD were common, and all patients were misdiagnosed as ITP, whereas the bleeding was mild and immunotherapy was ineffective. The suspected disease can be identified earlier by manual visual platelet volume and count, which can be confirmed by genetic testing. It is more important to monitor the development of other organs damage instead of thrombocytopenia. For cases with p.R702 mutations the doctor should be aware of kidney damage, and for the cases with novel mutations p.A44D the doctor should be aware of hearing loss.

Experimental investigation on buffer/backfill materials for radioactive waste repository downward facing sorption additivity of cesium, strontium and cobalt with different concentrations

Buffer/backfill materials for radioactive waste disposal sites consist of pure bentonite or bentonite-rock mixtures. In this study, the batch test method was used to obtain the sorption characteristics of important radionuclides such as Cs, Sr and Co on buffer/backfill materials; i. e., mixing Wyoming MX-80 bentonite or local Taiwanese Zhi-Shin bentonite with possible host rock (argillite and granite) in different proportions (0∼100%). The distribution coefficients (Kd) for Cs, Sr and Co were obtained from the experiments. The distribution coefficient for the bentonite-rock mixtures were found, with more than 50% of mixing proportion of bentonite to argillite or granite, to have very similar values to that of pure bentonite. Furthermore, it was clearly found that the sorption of Cs, Sr and Co to bentonite-rock mixtures is decreased as ionic strength of the liquid phase is increased from 0.001M to 1M for NaCl solutions. According to the experimental results, in synthetic groundwater, it is quite convenient and helpful to assess the distribution coefficients (Kd) of Cs, Sr and Co for buffer/backfill materials using batch sorption experiments with bentonite-rock mixtures of fixed mixing proportions.

Measurement of the Absolute Branching Fraction of D_{s}^{+}→τ^{+}ν_{τ} via τ^{+}→e^{+}ν_{e}ν[over ¯]_{τ}

Using a dataset of 6.32  fb^{-1} of e^{+}e^{-} annihilation data collected with the BESIII detector at center-of-mass energies between 4178 and 4226 MeV, we have measured the absolute branching fraction of the leptonic decay D_{s}^{+}→τ^{+}ν_{τ} via τ^{+}→e^{+}ν_{e}ν[over ¯]_{τ}, and find B_{D_{s}^{+}→τ^{+}ν_{τ}}=(5.27±0.10±0.12)×10^{-2}, where the first uncertainty is statistical and the second is systematic. The precision is improved by a factor of 2 compared to the previous best measurement. Combining with f_{D_{s}^{+}} from lattice quantum chromodynamics calculations or the |V_{cs}| from the CKMfitter group, we extract |V_{cs}|=0.978±0.009±0.012 and f_{D_{s}^{+}}=(251.1±2.4±3.0)  MeV, respectively. Combining our result with the world averages of B_{D_{s}^{+}→τ^{+}ν_{τ}} and B_{D_{s}^{+}→μ^{+}ν_{μ}}, we obtain the ratio of the branching fractions B_{D_{s}^{+}→τ^{+}ν_{τ}}/B_{D_{s}^{+}→μ^{+}ν_{μ}}=9.72±0.37, which is consistent with the standard model prediction of lepton flavor universality.

High-Risk HPV16 E6 Activates the cGMP/PKG Pathway Through Glycosyltransferase ST6GAL1 in Cervical Cancer Cells

Alterations in glycosylation regulate fundamental molecular and cellular processes of cancer, serving as important biomarkers and therapeutic targets. However, the potential association and regulatory mechanisms of E6 oncoprotein on glycosylation of cervical cancer cells are still unclear. Here, we evaluated the glycomic changes via using Lectin microarray and determined the corresponding enzymes associated with endogenous high-risk HPV16 E6 expression in cervical cancer cells. α-2,6 sialic acids and the corresponding glycosyltransferase ST6GAL1 were significantly increased in E6 stable-expressing HPV- cervical cancer C33A cells. Clinical validation further showed that the expression of ST6GAL1 was significantly increased in patients infected with high-risk HPV subtypes and showed a positive association with E6 in cervical scraping samples. Interfering ST6GAL1 expression markedly blocked the oncogenic effects of E6 on colony formulation, proliferation, and metastasis. Importantly, ST6GAL1 overexpression enhanced tumorigenic activities of both E6-positive and E6-negative cells. Mechanistical investigations revealed that E6 depended on activating YAP1 to stimulate ST6GAL1 expression, as verteporfin (inhibitor of YAP1) significantly suppressed the E6-induced ST6GAL1 upregulation. E6/ST6GAL1 triggered the activation of downstream cGMP/PKG signaling pathway and ODQ (inhibitor of GMP production) simultaneously suppressed the oncogenic activities of both E6 and ST6GAL1 in cervical cancer cells. Taken together, these findings indicate that ST6GAL1 is an important mediator for oncogenic E6 protein to activate the downstream cGMP/PKG signaling pathway, which represents a novel molecular mechanism and potential therapeutic targets for cervical cancer.

MiR-466 as a poor prognostic predictor suppresses cell proliferation and EMT in breast cancer cells by targeting PSMA7

OBJECTIVE

MiR-466 has been reported to exert a tumor-suppressive role in several cancers, including colorectal cancer and osteosarcoma, but its clinical significance and functional mechanisms in breast cancer (BC) pathogenesis still remain elusive.

PATIENTS AND METHODS

The expression of miR-466 was determined using reverse transcription quantitative PCR. The clinical significance of miR-466 in BC patients was assessed by Chi-square test, Kaplan-Meier method and Cox regression analyses. Functional experiments, including CCK-8 and transwell assays, were performed to analyze cell proliferation, migration and invasion ability. The association between miR-466 and proteasome subunit α7 (PSMA7) was confirmed by Luciferase reporter assay.

RESULTS

Here, we first observed that the expression of miR-466 was significantly downregulated in BC tissues and cell lines. The decreased miR-466 expression was significantly associated with tumor size (p = 0.003), lymph node metastasis (p = 0.008), TNM stage (p = 0.032) and poor survival rate. In addition, miR-466 was identified as an independent prognostic factor for BC patients. We further found that the overexpression of miR-466 significantly inhibited cell proliferation, migration and invasion. Mechanistically, PSMA7 was a potential target gene of miR-466 and negatively regulated miR-466 in BC cells. Oncomine database and Kaplan-Meier overall survival analysis indicated that upregulation of PSMA7 was associated with poor prognosis of BC patients. The rescue experiments demonstrated that PSMA7 overexpression reversed the effects of miR-466 on cell proliferation, migration, invasion and EMT transcription factors (E-cadherin, N-cadherin, and vimentin).

CONCLUSIONS

Collectively, these results suggest that the miR-466/PSMA7 axis might have potential as a therapeutic target for BC treatment.

Observation of D^{0}→K_{1}(1270)^{-}e^{+}ν_{e}

Using 2.93  fb^{-1} of e^{+}e^{-} collision data taken with the BESIII detector at a center-of-mass energy of 3.773 GeV, the observation of the D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} semileptonic decay is presented. The statistical significance of the decay D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} is greater than 10σ. The branching fraction of D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} is measured to be (1.09±0.13_{-0.16}^{+0.09}±0.12)×10^{-3}. Here, the first uncertainty is statistical, the second is systematic, and the third originates from the assumed branching fraction of K_{1}(1270)^{-}→K^{-}π^{+}π^{-}. The fraction of longitudinal polarization in D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} is determined for the first time to be 0.50±0.19_{stat}±0.08_{syst}.

First Measurement of the Absolute Branching Fraction of Λ→pμ^{-}ν[over ¯]_{μ}

The absolute branching fraction of Λ→pμ^{-}ν[over ¯]_{μ} is reported for the first time based on an e^{+}e^{-} annihilation sample of 10×10^{9}  J/ψ events collected with the BESIII detector at sqrt[s]=3.097  GeV. The branching fraction is determined to be B(Λ→pμ^{-}ν[over ¯]_{μ})=[1.48±0.21(stat)±0.08(syst)]×10^{-4}, which is improved by about 30% in precision over the previous indirect measurements. Combining this result with the world average of B(Λ→pe^{-}ν[over ¯]_{e}), we obtain the ratio {[Γ(Λ→pμ^{-}ν[over ¯]_{μ})]/[Γ(Λ→pe^{-}ν[over ¯]_{e})]} to be 0.178±0.028, which agrees with the standard model prediction assuming lepton flavor universality. The asymmetry of the branching fractions of Λ→pμ^{-}ν[over ¯]_{μ} and Λ[over ¯]→p[over ¯]μ^{+}ν_{μ} is also determined, and no evidence for CP violation is found.

[Infectious complications following chimeric antigen receptor T-cell therapy for a hematologic malignancy within 28 days]

Objective: To explore the incidence, clinical and microbiological characteristics and risk factors of infection in patients with acute lymphoblastic (ALL) , non-Hodgkin lymphoma (NHL) , and multiple myeloma (MM) within 28 days after CAR-T cell infusion. It provides data support for early identification of infection and the rational use of antibacterial drugs in these patients. Methods: We retrospectively analyzed the baseline data of 170 patients with ALL, NHL and MM who received chimeric antigen receptor-modified T (CAR-T) -cell treatment in the Department of Hematology of Wuhan Union Hospital from January 2016 to December 2020, and the clinical characteristics of infection within 28 days after infusion, including 72 patients with ALL, 56 patients with NHL, and 42 patients with MM; we used Poisson regression and Cox proportional hazard regression models to assess high-risk factors for infection before and after infusion, respectively. Results: Among 170 patients, 119 infections occurred in 99 patients within 28 days, with a cumulative infection rate of 58.2%. Seventy-eight patients had 98 bacterial infections and the cumulative incidence of bacterial infection was 45.9%. The infection density was 2.01, and the median time for the first infection was about 12 days after infusion. The adjusted baseline characteristic model showed that ALL patients, previous 30 days of infection history, refractory disease, absolute neutrophil count (ANC) <0.5×10(9)/L before infusion and ≥4 prior antitumor treatment regimens had a higher infection density within 28 days; grade 3 or 4 CRS was the only high-risk factor related to infection after infusion in the multivariate analysis. Conclusion: Infection is a common complication of CAR-T cell therapy in patients with hematologic malignancy. Bacterial infections occur in most patients regardless of the type of disease. ALL patients, previous 30 days of infection history, refractory disease, ANC<0.5×10(9)/L before infusion and grade 3 or 4 CRS are risk factors for infection. Chinese Clinical Trial Register:: ChiCTR-OIC-17011180, ChiCTR1800018143.

Observation of D_{s}^{±}/D^{0} Enhancement in Au+Au Collisions at sqrt[s_{NN}]=200 GeV

We report on the first measurement of charm-strange meson D_{s}^{±} production at midrapidity in Au+Au collisions at sqrt[s_{NN}]=200  GeV from the STAR experiment. The yield ratio between strange (D_{s}^{±}) and nonstrange (D^{0}) open-charm mesons is presented and compared to model calculations. A significant enhancement, relative to a pythia simulation of p+p collisions, is observed in the D_{s}^{±}/D^{0} yield ratio in Au+Au collisions over a large range of collision centralities. Model calculations incorporating abundant strange-quark production in the quark-gluon plasma and coalescence hadronization qualitatively reproduce the data. The transverse-momentum integrated yield ratio of D_{s}^{±}/D^{0} at midrapidity is consistent with a prediction from a statistical hadronization model with the parameters constrained by the yields of light and strange hadrons measured at the same collision energy. These results suggest that the coalescence of charm quarks with strange quarks in the quark-gluon plasma plays an important role in D_{s}^{±}-meson production in heavy-ion collisions.

Direct Measurement of the Branching Fractions B(ψ(3686)→J/ψX) and B(ψ(3770)→J/ψX), and Observation of the State R(3760) in e^{+}e^{-}→J/ψX

We report a measurement of the observed cross sections of e^{+}e^{-}→J/ψX based on 3.21  fb^{-1} of data accumulated at energies from 3.645 to 3.891 GeV with the BESIII detector operated at the BEPCII collider. In analysis of the cross sections, we measured the decay branching fractions of B(ψ(3686)→J/ψX)=(64.4±0.6±1.6)% and B(ψ(3770)→J/ψX)=(0.5±0.2±0.1)% for the first time. The energy-dependent line shape of these cross sections cannot be well described by two Breit-Wigner (BW) amplitudes of the expected decays ψ(3686)→J/ψX and ψ(3770)→J/ψX. Instead, it can be better described with one more BW amplitude of the decay R(3760)→J/ψX. Under this assumption, we extracted the R(3760) mass M_{R(3760)}=3766.2±3.8±0.4  MeV/c^{2} , total width Γ_{R(3760)}^{tot}=22.2±5.9±1.4  MeV, and product of leptonic width and decay branching fraction Γ_{R(3760)}^{ee}B[R(3760)→J/ψX]=(79.4±85.5±11.7)  eV. The significance of the R(3760) is 5.3σ. The first uncertainties of these measured quantities are from fits to the cross sections and second systematic.