Based on 4.4 fb -1 of e + e - annihilation data collected at the center-of-mass energies between 4.60 and 4.70 GeV with the BESIII detector at the BEPCII collider, the pure W-boson-exchange decay Λ c ...+ → Ξ 0 K + is studied with a full angular analysis. The corresponding decay asymmetry is measured for the first time to be α Ξ 0 K + = 0.01 ± 0.16(stat) ± 0.03(syst). This result reflects the noninterference effect between the S- and P-wave amplitudes. The phase shift between S- and P-wave amplitudes has two solutions, which are δ p - δ s = -1.55 ± 0.25(stat) ± 0.05(syst) rad or 1.59 ± 0.25(stat) ± 0.05(syst) rad.
This study was designed to analyze the outcomes of chemotherapy for high-risk gestational trophoblastic neoplasia (GTN) with EMA-CO regimen as primary and secondary protocol in China. Fifty-four ...patients with high-risk GTN received 292 EMA/CO treatment cycles between 1996 and 2005. Forty-five patients were primarily treated with EMA-CO, and nine were secondarily treated after failure to other combination chemotherapy. Adjuvant surgery and radiotherapy were used in the selected patients. Response, survival and related risk factors, as well as chemotherapy complications, were retrospectively analyzed. Thirty-five of forty-five patients (77.8%) receiving EMA-CO as first-line treatment achieved complete remission, and 77.8% (7/9) as secondary treatment. The overall survival rate was 87.0% in all high-risk GTN patients, with 93.3% (42/45) as primary therapy and 55.6% (5/9) as secondary therapy. The survival rates were significantly different between two groups (chi(2)= 6.434, P =0.011). Univariate analysis showed that the metastatic site and the number of metastatic organs were significant risk factors, but binomial distribution logistic regression analysis revealed that only the number of metastatic organs was an independent risk factor for the survival rate. No life-threatening toxicity and secondary malignancy were found. EMA-EP regimen was used for ten patients who were resistant to EMA-CO and three who relapsed after EMA-CO. Of those, 11 patients (84.6%) achieved complete remission. We conclude that EMA-CO regimen is an effective and safe primary therapy for high-risk GTN, but not an appropriate second-line protocol. The number of metastatic organs is an independent prognostic factor for the patient with high-risk GTN. EMA-EP regimen is a highly effective salvage therapy for those failing to EMA-CO.
