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11 results on '"Ma, T.L."'

5. New measurement of the Ge( , ) As reaction cross sections in the -process Nucleosynthesis

Author

Wu, D., Wang, N.Y., Guo, B., He, C.Y., Tian, Y., Tao, X., Ma, T.L., Liu, F.L., Yang, W.S., Wei, J.H., Shen, Y.P., Guo, S.L., Fan, Q.W., Wu, X.G., Zheng, Y., Li, T.X., Wang, Z.Q., Luo, H.L., Liu, Y.N., and Qiu, M.L.

Abstract

The $^{74}$Ge(p,γ)$^{75}$As reaction plays a crucial role in producing the lightest p-nucleus $^{74}$Se. In this work, we present the measurement of the $^{74}$Ge(p,γ)$^{75}$As cross sections in the range of Ep = 1.4-2.8 MeV with an in-beam method at the tandem accelerator of China Institute of Atomic Energy. The present result is in good agreement with the previous experiments at higher energies, and extends the measurement down to lower energies of astrophysical interest. Theoretical calculations are also performed using the EMPIRE nuclear reaction code and well reproduce all experimental cross sections, which shed some light on the existing discrepancy in the previously reported experimental and theoretical values at the lowest energies. The resulting reaction rates exhibit a considerable increase of up to 47% within the p-process relevant temperatures when comparing with the REACLIB compilation.

Published
2020

7. First experimental constraint of the spectroscopic amplitudes for the -cluster in the B ground state

Author

Shen, Y.P., Guo, B., Ma, T.L., Pang, D.Y., Ni, D.D., Ren, Z.Z., Li, Y.J., An, Z.D., Su, J., Liu, J.C., Fan, Q.W., Han, Z.Y., Li, X.Y., Li, Z.H., Lian, G., Su, Y., Wang, Y.B., Yan, S.Q., Zeng, S., and Liu, W.P.

Abstract

We present the first experimental determination on the spectroscopic amplitudes (SAs) for the α-cluster in the B11 ground state via the Li7(Li6,d)11B reaction using a high-precision magnetic spectrograph. This is believed to have a strong effect on the studies of α-induced reactions which are crucial in nuclear astrophysics. It is found that the previous SAs of B11 from shell model calculations cause overestimations of up to 23% for the C12(α,γ)16O SE2(300) factor and up to 34% for the C13(α,n)16O S(190) factor with respect to the results from the present experimentally determined SAs. Due to the importance of these two reactions, for example the uncertainty in the C12(α,γ)16O cross section at Ec.m. = 300 keV is required to be better than 10% by stellar modeling, the new S-factors could result in a potential influence on the astrophysical network calculations.

Published
2019

10. Validation and Comparison of Seven Mortality Prediction Models for Hospitalized Patients With Acute Decompensated Heart Failure.

Author

Lagu T, Pekow PS, Shieh MS, Stefan M, Pack QR, Kashef MA, Atreya AR, Valania G, Slawsky MT, and Lindenauer PK

Subjects
Acute Disease, Administrative Claims, Healthcare, Aged, Aged, 80 and over, Area Under Curve, Data Mining, Databases, Factual, Electronic Health Records, Female, Heart Failure diagnosis, Heart Failure physiopathology, Heart Failure therapy, Humans, Male, Middle Aged, Models, Statistical, Predictive Value of Tests, Prognosis, ROC Curve, Reproducibility of Results, Risk Assessment, Risk Factors, Time Factors, United States, Decision Support Techniques, Heart Failure mortality, Hospital Mortality, Hospitalization
Abstract

Background: Heart failure (HF) inpatient mortality prediction models can help clinicians make treatment decisions and researchers conduct observational studies; however, published models have not been validated in external populations., Methods and Results: We compared the performance of 7 models that predict inpatient mortality in patients hospitalized with acute decompensated heart failure: 4 HF-specific mortality prediction models developed from 3 clinical databases (ADHERE [Acute Decompensated Heart Failure National Registry], EFFECT study [Enhanced Feedback for Effective Cardiac Treatment], and GWTG-HF registry [Get With the Guidelines-Heart Failure]); 2 administrative HF mortality prediction models (Premier, Premier+); and a model that uses clinical data but is not specific for HF (Laboratory-Based Acute Physiology Score [LAPS2]). Using a multihospital, electronic health record-derived data set (HealthFacts [Cerner Corp], 2010-2012), we identified patients ≥18 years admitted with HF. Of 13 163 eligible patients, median age was 74 years; half were women; and 27% were black. In-hospital mortality was 4.3%. Model-predicted mortality ranges varied: Premier+ (0.8%-23.1%), LAPS2 (0.7%-19.0%), ADHERE (1.2%-17.4%), EFFECT (1.0%-12.8%), GWTG-Eapen (1.2%-13.8%), and GWTG-Peterson (1.1%-12.8%). The LAPS2 and Premier models outperformed the clinical models (C statistics: LAPS2 0.80 [95% confidence interval 0.78-0.82], Premier models 0.81 [95% confidence interval 0.79-0.83] and 0.76 [95% confidence interval 0.74-0.78], and clinical models 0.68 to 0.70)., Conclusions: Four clinically derived, inpatient, HF mortality models exhibited similar performance, with C statistics near 0.70. Three other models, 1 developed in electronic health record data and 2 developed in administrative data, also were predictive, with C statistics from 0.76 to 0.80. Because every model performed acceptably, the decision to use a given model should depend on practical concerns and intended use., (© 2016 American Heart Association, Inc.)

Published
2016
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