[Clinicopathological and molecular genetic characteristics of ELOC mutated renal cell carcinoma].

Objective: To investigate the clinicopathological features, molecular genetic features, differential diagnosis and prognosis of ELOC mutated renal cell carcinoma. Methods: From January 2015 to June 2022, 11 cases of renal cell carcinoma with clear-cell morphology, expression of CAⅨ and CK7 and no 3p deletion were collected. Two cases of ELOC mutant renal cell carcinoma were diagnosed using whole exome sequencing (WES). The clinical features, morphology, immunophenotype, FISH and WES results were analyzed. The relevant literature was reviewed. Results: The two patients were both male, aged 29 and 51 years, respectively. They were both found to have a renal mass by physical examination. The maximum diameters of the tumors were 3.5 cm and 2.0 cm, respectively. At the low magnification, the tumors were well-defined. The tumor cells showed a pushing border and were separated by thick fibrous bands, forming nodules. The tumor cells were arranged in a variety of patterns, including tubular, papillary, solid nest or alveolar. At high magnification, the tumor cells were large, with well-defined cell borders and clear cytoplasm or fine eosinophilic granules. CAⅨ was diffusely box-like positive in both cases. Case 1 was partially and moderately positive for CK7, strongly positive for CD10, diffusely and moderately positive for P504S, and weakly positive for 34ßE12. In case 2, CK7 and CD10 were both partially, moderately positive and P504s were diffusely positive, but 34ßE12 was negative. FISH results showed that both cases had no 3p deletion. ELOC c.235T>A (p.Y79N) mutation was identified using WES in case 1, while ELOC c.236_237inv (p.Y79C) mutation was identified in case 2. Conclusions: As a new clinical entity, ELOC mutated renal cell carcinoma may be underdiagnosed due to its overlap with clear cell renal cell carcinoma in morphology and immunophenotype. The diagnosis of renal cell carcinoma with ELOC mutation should be confirmed by morphology, immunohistochemistry, FISH and gene mutation detection. However, more additional cases are needed to explain its biological behavior and prognosis.

Deep Underground Laboratory Measurement of

The ^{13}C(α,n)^{16}O reaction is the main neutron source for the slow-neutron-capture process in asymptotic giant branch stars and for the intermediate process. Direct measurements at astrophysical energies in above-ground laboratories are hindered by the extremely small cross sections and vast cosmic-ray-induced background. We performed the first consistent direct measurement in the range of E_{c.m.}=0.24 to 1.9 MeV using the accelerators at the China Jinping Underground Laboratory and Sichuan University. Our measurement covers almost the entire intermediate process Gamow window in which the large uncertainty of the previous experiments has been reduced from 60% down to 15%, eliminates the large systematic uncertainty in the extrapolation arising from the inconsistency of existing datasets, and provides a more reliable reaction rate for the studies of the slow-neutron-capture and intermediate processes along with the first direct determination of the alpha strength for the near-threshold state.

[Research progress on infiltrating zone and microvascular invasion of hepatic alveolar echinococcosis].

Hepatic alveolar echinococcosis (AE) is a parasitic disease with biological characteristics similar to malignant tumor. It has no obvious clinical symptoms in the early stage. Most patients have complications such as jaundice, ascites and gastrointestinal bleeding when they see a doctor. At this time, the course of disease is at an advanced stage. In addition, the incomplete resection of the AE lesion(s) leads to a high postoperative recurrence rate, which has a serious impact on the physical and mental health of patients. Based on the summary of the latest research at home and abroad and the analysis of blood supply, microvascular invasion and vascular growth factor expression in the "infiltrating zone" adjacent to the lesions of hepatic AE, this article has a deep understanding of the occurrence and development process of hepatic AE, aiming to better guide clinical practice and improve the quality of life of patients.

Sonographic evaluation of normal diaphragmatic thickness and excursion in Malaysia paediatric population: A single-institution cross-sectional study.

INTRODUCTION: Diaphragmatic dysfunction is often underdiagnosed as clinical presentation is non-specific and reference values for normal diaphragmatic excursion are inadequate. The rationale of this study is to provide a normal reference value of diaphragmatic excursion and thickness in Malaysia's paediatric population using M-mode sonography, as no previous local data are available to our knowledge. MATERIALS AND METHODS: A total of 119 healthy infants and children fulfilling our inclusion and exclusion criteria were recruited. They were divided into three groups according to age - 0-2 years old in group 1; 2-6 years old in group 2; 6- 12 years old in group 3. Sonography B-mode was used to assess bilateral diaphragmatic thickness and M-mode to assess diaphragmatic excursion during quiet spontaneous respiration. RESULTS: In our paediatric population, the normal right and left diaphragmatic thickness were 2.0 mm ± 0.5 and 2.0 mm ± 0.5 for group 1; 2.5 mm ± 0.8 and 2.4 mm ± 0.6 for group 2; 2.7 mm ± 0.7 and 2.5 mm ± 0.5 for group 3, respectively. The normal right and left diaphragmatic excursion were 7.7 mm ± 2.5 and 7.3 mm ± 2.6 for group 1; 11.5 mm ± 3.8 and 10.6 mm ± 3.8 for group 2; 13.8 mm ± 3.9 and 12.9 mm ± 3.3 for group 3, respectively (data presented in mean ± standard deviation). There were no significant differences between two genders for each group. Significant positive correlation between age, weight, height, and body surface area with bilateral diaphragmatic thickness and excursion were detected in all studied population. The percentage difference between excursions of both hemidiaphragm was below 40%. CONCLUSIONS: M-mode sonography is the modality of choice for diaphragmatic kinetics especially in paediatric population. This study provides normal sonographic reference value of diaphragmatic excursion and thickness in the Malaysian paediatric population as well as percentile curves for right diaphragmatic excursion plotted against body weight. The availability of this data will aid in the diagnosis of diaphragmatic dysfunction and hence immediate intervention for better recovery.

[Analysis of the clinical characteristics and species distribution of non-tuberculous mycobacteria in a general hospital].

Objective: To summarize the clinical characteristics and species distribution of nontuberculous mycobacteria(NTM). Methods: We conducted a retrospectively chart review of 453 adult patients with 532 positive cultures with NTM diagnosed and treated in Peking Union Medical College Hospital from January 2014 to December 2018. The information including clinical findings, imaging and etiological data were obtained from clinical examination system. Among these 453 patients, 75 cases met the diagnostic criteria for NTM, with detailed clinical data, culture results and radiological images. Of these patients, 38 were males and 37 were females, with an average age of (50.8±16.2) years. Clinical manifestations, imaging features, NTM species and treatment were analyzed. Results: Among 75 NTM patients, 43 cases (57.3%, 43/75) were infected with Mycobacterium avium Complex (MAC)/intracellular, 18 cases (24.0%, 18/75) with Mycobacterium turtle/abscess, and 7 cases (9.3%, 7/75) with Mycobacterium kansasii. Comorbidities existed in 64.0% patients (48/75). The top two common comorbidities were previous tuberculosis (25.3%, 19/75) infection and clinical bronchiectasis (18.7%, 14/75). After the respiratory disease (82.7%, 62/75), we identified bloodstream as the most frequent manifestation of NTM infection (25.3%, 19/75). MAC was often associated with infection in respiratory system and bloodstream, while rapidly growing mycobacteria (RGM) was more commonly detected in lymph nodes and skin and soft tissues. Cough/expectoration (77.4%, 48/62) was the most common clinical symptom of NTM disease, followed by fever and dyspnea. The frequent imaging findings were nodules (41.9%, 26/62), bronchiectasis (37.1%, 23/62), and fibrous cavities (24.2%, 15/62). In disseminated NTM disease, 94.7% (18/19) patients had underlying diseases and 89.5% (17/19) patients had long-term immunosuppression. Conclusion: The most common NTM species was Mycobacterium avium/intracellular in our series. The predominant infected organ was the respiratory system. Previous tuberculosis history likely increased the risk of infection.

Measurement of the Cross Section for e

Using a total of 11.0 fb^{-1} of e^{+}e^{-} collision data with center-of-mass energies between 4.009 and 4.6 GeV and collected with the BESIII detector at BEPCII, we measure fifteen exclusive cross sections and effective form factors for the process e^{+}e^{-}→Ξ^{-}Ξ[over ¯]^{+} by means of a single baryon-tag method. After performing a fit to the dressed cross section of e^{+}e^{-}→Ξ^{-}Ξ[over ¯]^{+}, no significant ψ(4230) or ψ(4260) resonance is observed in the Ξ^{-}Ξ[over ¯]^{+} final states, and upper limits at the 90% confidence level on Γ_{ee}B for the processes ψ(4230)/ψ(4260)→Ξ^{-}Ξ[over ¯]^{+} are determined. In addition, an excited Ξ baryon at 1820 MeV/c^{2} is observed with a statistical significance of 6.2-6.5σ by including the systematic uncertainty, and the mass and width are measured to be M=(1825.5±4.7±4.7) MeV/c^{2} and Γ=(17.0±15.0±7.9) MeV, which confirms the existence of the J^{P}=3/2^{-} state Ξ(1820).

Measurement of Proton Electromagnetic Form Factors in e

The process of e^{+}e^{-}→pp[over ¯] is studied at 22 center-of-mass energy points (sqrt[s]) from 2.00 to 3.08 GeV, exploiting 688.5 pb^{-1} of data collected with the BESIII detector operating at the BEPCII collider. The Born cross section (σ_{pp[over ¯]}) of e^{+}e^{-}→pp[over ¯] is measured with the energy-scan technique and it is found to be consistent with previously published data, but with much improved accuracy. In addition, the electromagnetic form-factor ratio (|G_{E}/G_{M}|) and the value of the effective (|G_{eff}|), electric (|G_{E}|), and magnetic (|G_{M}|) form factors are measured by studying the helicity angle of the proton at 16 center-of-mass energy points. |G_{E}/G_{M}| and |G_{M}| are determined with high accuracy, providing uncertainties comparable to data in the spacelike region, and |G_{E}| is measured for the first time. We reach unprecedented accuracy, and precision results in the timelike region provide information to improve our understanding of the proton inner structure and to test theoretical models which depend on nonperturbative quantum chromodynamics.

Determination of Strong-Phase Parameters in D→K_{S,L}

We report the most precise measurements to date of the strong-phase parameters between D^{0} and D[over ¯]^{0} decays to K_{S,L}^{0}π^{+}π^{-} using a sample of 2.93 fb^{-1} of e^{+}e^{-} annihilation data collected at a center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider. Our results provide the key inputs for a binned model-independent determination of the Cabibbo-Kobayashi-Maskawa angle γ/ϕ_{3} with B decays. Using our results, the decay model sensitivity to the γ/ϕ_{3} measurement is expected to be between 0.7° and 1.2°, approximately a factor of three smaller than that achievable with previous measurements, based on the studies of the simulated data. The improved precision of this work ensures that measurements of γ/ϕ_{3} will not be limited by knowledge of strong phases for the next decade. Furthermore, our results provide critical input for other flavor-physics investigations, including charm mixing, other measurements of CP violation, and the measurement of strong-phase parameters for other D-decay modes.

[Population's acceptance and attitude toward a novel fecal immunochemical test for colorectal cancer screening: a multi-center survey in China].

Objective: To investigate the acceptance and attitude toward a novel fecal immunochemical test (FIT) in colorectal cancer screening among populations in China. Methods: From May 2018 to May 2019, 2 474 people aged 50-74 years were recruited from five provinces of China (Zhejiang, Anhui, Jiangsu, Hunan and Yunnan). The general demographic characteristics, acceptance of the new FIT technology and operational difficulties through the whole screening process were obtained through questionnaire survey. Multivariate logistic regression model was used to analyze the factors related to difficulties encountered in sampling stool, reading and uploading results. Results: The subjects were (60.0±6.4) years old, and female, high school of above educated, unemployed/retired/other, married and with medical insurance status of "new rural cooperative medical care (NRCMC)" accounted for 61.7% (1 526), 29.0%(718), 34.3% (849), 92.7% (2 293) and 31.3%(775), respectively. The population's acceptance of the FIT technology was 94.8%. In the process of FIT screening, the percentage of occurred difficulties in sampling stool, reading and uploading results were 33.1% (819), 46.4% (1 147) and 62.9% (1 557), respectively. The main difficulties were the uncertainty about whether the sampling operation was standard (28.0%), the inability to accurately judge the result displayed (32.5%) and the need for help without using a smartphone (44.2%). The results of multivariate logistic regression model analysis showed that people aged 65-74 years old and with medical insurance status of "NRCMC" were more likely to encounter difficulties in sampling, and those who were unemployed/retired/other and living with 3 or more family members were less likely to encounter difficulties in sampling. Those aged 65-74 years old, farmers or migrant workers, and those with "NRCMC" were more likely to encounter difficulties in readingresults, and those with 3 or more family members were less likely to encounter difficulties in reading result. Those with "NRCMC" were more likely to encounter difficulties in uploading results, and those with education level of high school or above, living with more than 3 family members were less likely to encounter difficulties in uploading results. Conclusion: The acceptance of the new FIT technology is relatively high among the subjects. Age, education level, occupation, number of family members living together and medical insurance status might be related to difficulties encountered in sampling stool, reading and uploading results, and it can be further strengthened in terms of the technology and characteristics of sub-populations.

[Detection and comparison of fiber count concentration in processing environment of asbestos and man-made mineral fiber].

Objective: To connect with the measurement data of asbestos dust fiber concentration in foreign countries, improve the accuracy of asbestos fiber detection in China, and understand the dust exposure in the working environment of asbestos and man-made mineral fiber production and processing sites in Zhejiang Province. The fiber count concentrations of working environment in glass fiber, ceramic fiber and asbestos processing plants were measured and compared. Methods: The dust concentration in the working environment of two glass fiber factories, one ceramic fiber factory and eight asbestos products processing factories was measured. The total dust mass concentration was measured according to GBZ/T 192.1-2007, and the fiber count concentration was measured by phase contrast microscope. Kruskal Wallis was used to test and compare the dust concentration in the working environment of each post. The correlation between asbestos mass concentration and fiber count concentration was analyzed by Spearman correlation. Results: Under the phase contrast microscope, there were many short and fine asbestos fibers in the field of vision, and there were many impurities around. The average dust concentration of asbestos processing plant was 3.2 f/ml, and the dust concentration of cotton ginning was the highest (6.68 f/ml) . There was a significantly positive correlation between asbestos fiber count concentration and mass concentration (r=0.535, P=0.033) . The average fiber count concentration of glass fiber factory was 0.001 f/ml, and the highest was 0.005 f/ml. The average fiber count concentration of ceramic fiber factory was 0.001 f/ml, and the highest was 0.006 f/ml. Conclusion: The fiber count concentration in the working environment of asbestos factory in Zhejiang Province is obviously over the standard, which is one of the important reasons for the high incidence of mesothelioma in this area. Short and small asbestos fibers are easy to be ignored when counting. It is necessary to improve the actual operation process of fiber counting to form a laboratory standard in China.

Observation of the Decay X(3872)→π

Using a total of 9.0 fb^{-1} of e^{+}e^{-} collision data with center-of-mass energies between 4.15 and 4.30 GeV collected by the BESIII detector, we search for the processes e^{+}e^{-}→γX(3872) with X(3872)→π^{0}χ_{cJ} for J=0, 1, 2. We report the first observation of X(3872)→π^{0}χ_{c1}, a new decay mode of the X(3872), with a statistical significance of more than 5σ for all systematic fit variations. Normalizing to the previously established process e^{+}e^{-}→γX(3872) with X(3872)→π^{+}π^{-}J/ψ, we find B(X(3872)→π^{0}χ_{c1})/B(X(3872)→π^{+}π^{-}J/ψ)=0.88_{-0.27}^{+0.33}±0.10, where the first error is statistical and the second is systematic. We set 90% confidence level upper limits on the corresponding ratios for the decays to π^{0}χ_{c0} and π^{0}χ_{c2} of 19 and 1.1, respectively.

Observation of D

Using a data sample corresponding to an integrated luminosity of 2.93 fb^{-1} recorded by the BESIII detector at a center-of-mass energy of 3.773 GeV, we present an analysis of the decays D^{0}→π^{-}π^{0}e^{+}ν_{e} and D^{+}→π^{-}π^{+}e^{+}ν_{e}. By performing a partial wave analysis, the π^{+}π^{-} S-wave contribution to D^{+}→π^{-}π^{+}e^{+}ν_{e} is observed to be (25.7±1.6±1.1)% with a statistical significance greater than 10σ, besides the dominant P-wave contribution. This is the first observation of the S-wave contribution. We measure the branching fractions B(D^{0}→ρ^{-}e^{+}ν_{e})=(1.445±0.058±0.039)×10^{-3}, B(D^{+}→ρ^{0}e^{+}ν_{e})=(1.860±0.070±0.061)×10^{-3}, and B(D^{+}→f_{0}(500)e^{+}ν_{e},f_{0}(500)→π^{+}π^{-})=(6.30±0.43±0.32)×10^{-4}. An upper limit of B(D^{+}→f_{0}(980)e^{+}ν_{e},f_{0}(980)→π^{+}π^{-})<2.8×10^{-5} is set at the 90% confidence level. We also obtain the hadronic form factor ratios of D→ρe^{+}ν_{e} at q^{2}=0 assuming the single-pole dominance parametrization: r_{V}={[V(0)]/[A_{1}(0)]}=1.695±0.083±0.051, r_{2}={[A_{2}(0)]/[A_{1}(0)]}=0.845±0.056±0.039.

First Measurement of the Form Factors in D_{s}

We report on new measurements of Cabibbo-suppressed semileptonic D_{s}^{+} decays using 3.19 fb^{-1} of e^{+}e^{-} annihilation data sample collected at a center-of-mass energy of 4.178 GeV with the BESIII detector at the BEPCII collider. Our results include branching fractions B(D_{s}^{+}→K^{0}e^{+}ν_{e})=[3.25±0.38(stat)±0.16(syst)]×10^{-3} and B(D_{s}^{+}→K^{*0}e^{+}ν_{e})=[2.37±0.26(stat)±0.20(syst)]×10^{-3}, which are much improved relative to previous measurements, and the first measurements of the hadronic form-factor parameters for these decays. For D_{s}^{+}→K^{0}e^{+}ν_{e}, we obtain f_{+}(0)=0.720±0.084(stat)±0.013(syst), and for D_{s}^{+}→K^{*0}e^{+}ν_{e}, we find form-factor ratios r_{V}=V(0)/A_{1}(0)=1.67±0.34(stat)±0.16(syst) and r_{2}=A_{2}(0)/A_{1}(0)=0.77±0.28(stat)±0.07(syst).

Study of e

We study the e^{+}e^{-}→γωJ/ψ process using 11.6 fb^{-1} e^{+}e^{-} annihilation data taken at center-of-mass energies from sqrt[s]=4.008 GeV to 4.600 GeV with the BESIII detector at the BEPCII storage ring. The X(3872) resonance is observed for the first time in the ωJ/ψ system with a significance of more than 5σ. The relative decay ratio of X(3872)→ωJ/ψ and π^{+}π^{-}J/ψ is measured to be R=1.6_{-0.3}^{+0.4}±0.2, where the first uncertainty is statistical and the second systematic (the same hereafter). The sqrt[s]-dependent cross section of e^{+}e^{-}→γX(3872) is also measured and investigated, and it can be described by a single Breit-Wigner resonance, referred to as the Y(4200), with a mass of 4200.6_{-13.3}^{+7.9}±3.0 MeV/c^{2} and a width of 115_{-26}^{+38}±12 MeV. In addition, to describe the ωJ/ψ mass distribution above 3.9 GeV/c^{2}, we need at least one additional Breit-Wigner resonance, labeled as X(3915), in the fit. The mass and width of the X(3915) are determined. The resonant parameters of the X(3915) agree with those of the Y(3940) in B→KωJ/ψ and of the X(3915) in γγ→ωJ/ψ observed by the Belle and BABAR experiments within errors.

Precision Measurement of the Branching Fractions of η

Based on a sample of (1310.6±7.0)×10^{6}J/ψ events collected with the BESIII detector, we present measurements of J/ψ and η^{'} absolute branching fractions using the process J/ψ→γη^{'}. By analyzing events where the radiative photon converts into an e^{+}e^{-} pair, the branching fraction for J/ψ→γη^{'} is measured to be (5.27±0.03±0.05)×10^{-3}. The absolute branching fractions of the five dominant decay channels of the η^{'} are then measured for the first time and are determined to be B(η^{'}→γπ^{+}π^{-})=(29.90±0.03±0.55)%, B(η^{'}→ηπ^{+}π^{-})=(41.24±0.08±1.24)%, B(η^{'}→ηπ^{0}π^{0})=(21.36±0.10±0.92)%, B(η^{'}→γω)=(2.489±0.018±0.074)%, and B(η^{'}→γγ)=(2.331±0.012±0.035)%, where the first uncertainties are statistical and the second systematic.

Measurement of the Dynamics of the Decays D_{s}

Using e^{+}e^{-} annihilation data corresponding to an integrated luminosity of 3.19 fb^{-1} collected at a center-of-mass energy of 4.178 GeV with the BESIII detector, we measure the absolute branching fractions B_{D_{s}^{+}→ηe^{+}ν_{e}}=(2.323±0.063_{stat}±0.063_{syst})% and B_{D_{s}^{+}→η^{'}e^{+}ν_{e}}=(0.824±0.073_{stat}±0.027_{syst})% via a tagged analysis technique, where one D_{s} is fully reconstructed in a hadronic mode. Combining these measurements with previous BESIII measurements of B_{D^{+}→η^{(')}e^{+}ν_{e}}, the η-η^{'} mixing angle in the quark flavor basis is determined to be ϕ_{P}=(40.1±2.1_{stat}±0.7_{syst})°. From the first measurements of the dynamics of D_{s}^{+}→η^{(')}e^{+}ν_{e} decays, the products of the hadronic form factors f_{+}^{η^{(')}}(0) and the Cabibbo-Kobayashi-Maskawa matrix element |V_{cs}| are determined with different form factor parametrizations. For the two-parameter series expansion, the results are f_{+}^{η}(0)|V_{cs}|=0.4455±0.0053_{stat}±0.0044_{syst} and f_{+}^{η^{'}}(0)|V_{cs}|=0.477±0.049_{stat}±0.011_{syst}.

Study of the D

Using e^{+}e^{-} annihilation data of 2.93 fb^{-1} collected at center-of-mass energy sqrt[s]=3.773 GeV with the BESIII detector, we measure the absolute branching fraction of D^{0}→K^{-}µ^{+}ν_{µ} with significantly improved precision: B_{D^{0}→K^{-}µ^{+}ν_{µ}}=(3.413±0.019_{stat}±0.035_{syst})%. Combining with our previous measurement of B_{D^{0}→K^{-}e^{+}ν_{e}}, the ratio of the two branching fractions is determined to be B_{D^{0}→K^{-}µ^{+}ν_{µ}}/B_{D^{0}→K^{-}e^{+}ν_{e}}=0.974±0.007_{stat}±0.012_{syst}, which agrees with the theoretical expectation of lepton flavor universality within the uncertainty. A study of the ratio of the two branching fractions in different four-momentum transfer regions is also performed, and no evidence for lepton flavor universality violation is found with current statistics. Taking inputs from global fit in the standard model and lattice quantum chromodynamics separately, we determine f_{+}^{K}(0)=0.7327±0.0039_{stat}±0.0030_{syst} and |V_{cs}|=0.955±0.005_{stat}±0.004_{syst}±0.024_{LQCD}.

Evidence of a Resonant Structure in the e

The cross section of the process e^{+}e^{-}→π^{+}D^{0}D^{*-} for center-of-mass energies from 4.05 to 4.60 GeV is measured precisely using data samples collected with the BESIII detector operating at the BEPCII storage ring. Two enhancements are clearly visible in the cross section around 4.23 and 4.40 GeV. Using several models to describe the dressed cross section yields stable parameters for the first enhancement, which has a mass of 4228.6±4.1±6.3 MeV/c^{2} and a width of 77.0±6.8±6.3 MeV, where the first uncertainties are statistical and the second ones are systematic. Our resonant mass is consistent with previous observations of the Y(4220) state and the theoretical prediction of a DD[over ¯]_{1}(2420) molecule. This result is the first observation of Y(4220) associated with an open-charm final state. Fits with three resonance functions with additional Y(4260), Y(4320), Y(4360), ψ(4415), or a new resonance do not show significant contributions from either of these resonances. The second enhancement is not from a single known resonance. It could contain contributions from ψ(4415) and other resonances, and a detailed amplitude analysis is required to better understand this enhancement.

Observation of the Leptonic Decay D

We report the first observation of D^{+}→τ^{+}ν_{τ} with a significance of 5.1σ. We measure B(D^{+}→τ^{+}ν_{τ})=(1.20±0.24_{stat}±0.12_{syst})×10^{-3}. Taking the world average B(D^{+}→µ^{+}ν_{µ})=(3.74±0.17)×10^{-4}, we obtain R_{τ/µ}=Γ(D^{+}→τ^{+}ν_{τ})/Γ(D^{+}→µ^{+}ν_{µ})=3.21±0.64_{stat}±0.43_{syst}., which is consistent with the standard model expectation of lepton flavor universality. Using external inputs, our results give values for the D^{+} decay constant f_{D^{+}} and the Cabibbo-Kobayashi-Maskawa matrix element |V_{cd}| that are consistent with, but less precise than, other determinations.

Observation of the Semileptonic D

By analyzing a 2.93 fb^{-1} data sample of e^{+}e^{-} collisions, recorded at a center-of-mass energy of 3.773 GeV with the BESIII detector operated at the BEPCII collider, we report the first observation of the semileptonic D^{+} transition into the axial-vector meson D^{+}→K[over ¯]_{1}(1270)^{0}e^{+}ν_{e} with a statistical significance greater than 10σ. Its decay branching fraction is determined to be B[D^{+}→K[over ¯]_{1}(1270)^{0}e^{+}ν_{e}]=(2.30±0.26_{-0.21}^{+0.18}±0.25)×10^{-3}, where the first and second uncertainties are statistical and systematic, respectively, and the third originates from the input branching fraction of K[over ¯]_{1}(1270)^{0}→K^{-}π^{+}π^{0}.