This study constructed a technique effectiveness evaluation formula for table tennis players based on the relationship between the scoring rate and usage rate of techniques and established the evaluation criteria through the examination of 224 matches of the world's top 35 players. It also built a competition performance formula with the score difference theory for the exploration of the correlation between player technique effectiveness and competition performance. The results showed the three indices--the technique effectiveness of the first and third strokes (TE₁,₃), the second and fourth strokes (TE₂,₄) and the after fourth strokes (TE(>₄))--could help better evaluate the technique effectiveness of elite players. The comparative analysis of Chinese elite table tennis players and players from other countries and regions revealed that Chinese players as a whole were "excellent" in all the examined techniques except in the male's "first and third strokes"; while players from other countries and regions were overall "general". The case analysis of two world top players further indicated that correlation analysis of technique effectiveness and competition performance could help identify the technique indices highly correlated with player competition performance.

Effective diagnosis and clinical management of placenta accreta (PA) in China are not clear. The purpose of the study was to analyze the risk factors and diagnosis of PA, maternal and neonatal outcomes in patients with PA. It was a retrospective study of cases with PA, confirmed by histologically and/or clinically suspected during 3 years in 2 tertiary referral hospitals. The incidence rate of patients with PA, who had history of artificial abortion, cesarean section (CS), and placenta previa (PP) was 94%, 70%, and 72%, respectively. In 29 patients of scheduled CS group, 12 cases were performed with cesarean hysterectomy. Mean estimated blood loss (EBL) was 1.5 L, and 17 babies were admitted to neonatal intensive care unit (NICU). In the 18 cases of emergency CS group, 6 cases were performed cesarean hysterectomy. Mean EBL was 2.4 L, and 16 babies were admitted to NICU. The difference of mean EBL, cases of fetal admitted to intensive care unit in 2 groups was significant difference (P < .05).Women with history of uterine curettage, CS or PP are more likely to have PA. PA should be diagnosed early and accurately via ultrasound and magnetic resonance imaging. Maternal and neonatal outcomes in the scheduled CS are better than in emergency CS. Emergency peripartum hysterectomy is a feasible method under the circumstances of heave, fast bleeding, and the failure of conservative surgery.

This study constructed a technique effectiveness evaluation formula for table tennis players based on the relationship between the scoring rate and usage rate of techniques and established evaluation criteria through the examination of 224 matches of the world's top 35 players. It also built a competition performance formula with the score difference theory for the exploration of the correlation between player technique effectiveness and competition performance. The results showed the three indices - the technique effectiveness of the first and third strokes (TE₁,₃), the second and fourth strokes (TE₂,₄) and the after fourth strokes (TE>₄) - could help better evaluate the technique effectiveness of elite players. The comparative analysis of Chinese elite table tennis players and players from other countries and regions revealed that Chinese players as a whole were 'excellent' in all the examined techniques except in the male's 'first and third strokes'; while players from other countries and regions were overall 'general'. The case analysis of two of the world's top players further indicated that correlation analysis of technique effectiveness and competition performance could help identify the technique indices highly correlated with player competition performance.

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