Spinal and supraspinal motor control predictors of rate of torque development

During explosive movements and potentially injurious situations, the ability to rapidly generate torque is critical. Previous research has suggested that different phases of rate of torque development (RTD) are differentiately controlled. However, the extent to which supraspinal and spinal mechanisms predict RTD at different time intervals is unknown. RTD of the plantarflexors across various phases of contraction (i.e., 0–25, 0–50, 0–100, 0–150, 0–200, and 0–250 ms) was measured in 37 participants. The following predictor variables were also measured: (a) gain of the resting soleus H‐reflex recruitment curve; (b) gain of the resting homonymous post‐activation depression recruitment curve; (c) gain of the GABAergic presynaptic inhibition recruitment curve; (d) the level of postsynaptic recurrent inhibition at rest; (e) level of supraspinal drive assessed by measuring V waves; and (f) the gain of the resting soleus M wave. Stepwise regression analyses were used to determine which variables significantly predicted allometrically scaled RTD. The analyses indicated that supraspinal drive was the dominant predictor of RTD across all phases. Additionally, recurrent inhibition predicted RTD in all of the time intervals except 0–150 ms. These results demonstrate the importance of supraspinal drive and recurrent inhibition to RTD.     

口腔正畸联合修复治疗错伴牙缺损的临床应用效果探讨

目的探讨口腔正畸联合修复治疗错伴牙缺损的临床应用效果。方法82例错伴牙缺损患者,按治疗方式的不同分为单一组和联合组,每组41例。单一组给予单一口腔修复治疗,联合组给予口腔正畸联合修复治疗。对比两组治疗前后的菌斑指数、软垢指数、咀嚼效率、咬合力及治疗优良率、不良事件(牙齿移位、牙齿松动、牙列间隙)发生率。结果治疗后,联合组的菌斑指数(0.56±0.17)、软垢指数(0.62±0.14)低于单一组的(1.25±0.24)、(1.36±0.20),咀嚼效率(91.20±6.81)%、咬合力(55.62±4.25)kg高于单一组的(78.52±7.14)%、(45.21±4.18)kg,差异均有统计学意义(P<0.05)。治疗后,联合组的治疗优良率95.12%高于单一组的78.05%,差异有统计学意义(P<0.05)。联合组的不良事件发生率4.88%低于单一组的19.51%,差异有统计学意义(P<0.05)。结论错伴牙缺损患者通过口腔正畸联合修复治疗,可有效提升其咀嚼效率、咬合力,改善其口腔卫生,治疗效果显著,并能减少牙齿移位、牙齿松动、牙列间隙等不良事件的发生。     

声脉冲辐射力弹性成像技术对甲状腺良恶性结节的鉴别诊断价值

目的   探讨声脉冲辐射力弹性成像技术（ARFI）用于鉴别诊断甲状腺良、恶性结节的临床应用价值。方法  选取2015年6月至2016年9月在河南科技大学第一附属医院拟行甲状腺结节切除手术的68例患者（共99个结节）,对其影像学资料进行回顾性分析。患者术前行ARFI检查,观察并记录ARFI技术剪切波的速度（SWV）值,分析良性和恶性结节、病变结节同周边无病变组织间SWV值的差异。采用受试者工作特征曲线（ROC）获取鉴别甲状腺良、恶性结节SWV值的截断值,以病理组织学诊断结果 作为金标准,分析ARFI技术对诊断良、恶性结节性甲状腺病灶的灵敏度、特异度、准确率、阳性预测值及阴性预测值。结果 甲状腺良性、恶性结节及周边正常甲状腺组织的SWV平均值分别为（2.68±0.51）m／s、（3.09±0.53）m／s和 （2.42±0.22）m／s,恶性结节的SWV值高于良性结节,差异有统计学意义（P＜0.001）,甲状腺良、恶性结节SWV值均高于周边正常组织,差异有统计学意义（P＜0.001）。甲状腺良性结节和恶性结节与周围组织的SWV比值分别为（1.108±0.205）、（1.277±0.258）,差异有统计学意义（P＜0.001）。SWV值诊断甲状腺病灶良、恶性的灵敏度、特异度、准确率、阳性预测值及阴性预测值分别为63.41％、74.14％、69.70％、63.41％和74.14％。SWV比值诊断良、恶性甲状腺结节的灵敏度、特异度、准确率、阳性预测值及阴性预测值分别为58.54％、79.31％、69.70％、64.86％和72.58％。结论 ARFI技术作为一项无创技术用于鉴别结节性甲状腺病灶的良、恶性有很高的临床应用价值,能够被广泛应用于临床初步鉴别结节性甲状腺病灶。     

EMG amplitude,fatigue threshold,and time to task failure: A meta-analysis

Objectives

Electromyographic (EMG) fatigue threshold (EMG_FT) is utilised as a correlate of critical power, torque, and force thresholds that establishes a theoretical exercise intensity—the power, torque, or force at which the rate of change of EMG amplitude (ΔE$\overline{\mathrm{M}}$G) is zero—below which neuromuscular fatigue is negligible and unpredictable. Recent studies demonstrating neuromuscular fatigue below critical thresholds raise questions about the construct validity of EMG_FT. The purpose of this analysis is to evaluate the construct validity of EMGFT by aggregating ΔE$\overline{\mathrm{M}}$G and time to task failure (T_lim) data.

两种椎管内阻滞方法用于分娩镇痛的临床比较

目的探讨采用蛛网膜下腔与硬膜外腔分段阻滞联合用药及单纯硬膜外腔用药法的镇痛效果及其对母婴的影响。方法以蛛网膜下腔与硬膜外腔分段阻滞联合用药分娩镇痛者为研究组（１００例）,单纯硬膜外麻醉分娩镇痛者为对照组（４０例）,分别观察疼痛程度、副作用、产程时间、分娩方式、产后出血、胎儿窘迫及新生儿窒息情况。结果两组镇痛效果比较,差异有极显著性（Ｐ＜００１）,两组产程时间均值比较,差异无显著性（Ｐ＞００５）;两组产妇分娩方式、产后出血率、胎儿宫内窘迫及新生儿窒息发生率比较,差异无显著性（Ｐ＞００５）。结论蛛网膜下腔与硬膜外腔分段阻滞联合用药法,用于分娩镇痛安全有效。对产程及母婴均无影响,较单纯硬膜外麻醉镇痛效果更为肯定、满意,可在有一定条件的医疗单位应用。