Determining the number of repetitions to establish isokinetic knee evaluation protocols specific to angular velocities of 60°/second and 180°/second

IntroductionThis study aims to develop a standard number of repetition at angular velocities of 60°/sec and 180°/sec and define the difference of number of repetitions between genders.MethodOne hundred ninety-six athletes (judo, volleyball, Greco-Roman wrestling, runners, and gymnastics) were involved. Concentric-concentric isokinetic muscle strength of the knee flexor-extensor muscles of the athletes were performed with an ISOMED 2000 isokinetic dynamometer. The evaluation test protocol consisted of 10 repetition of knee flexion-extension at 60°/sec and 30 repetitions at 180°/sec.ResultsAthletes performed with maximal knee flexion strength at their second and third trial at 60°/sec and third-forth trial at 180°/sec. It was found that 2 repetitions and 2–3 repetitions were needed for knee extension peak torque at 60°/sec and 180°/sec respectively. The difference between the genders was significant at 60°/sec for knee flexion and extension on the dominant side; at 180°/sec for knee extension on the dominant and non-dominant side. It was determined that 3 repetitions for 60°/sec, 4 repetitions for 180°/sec were enough to determine peak torque values.DiscussionOptimal number of repetitions is crucial so that athletes could have the opportunity to reach maximal strength without unnecessary workload or waste of time.ConclusionsProtocols involving 3 repetitions for 60°/sec, 4 repetitions for 180°/sec were enough to determine peak torque values. Gender of athletes should be considered when establishing isokinetic knee evaluation protocols.     

Effects of proprioceptive training on ankle muscle strength in fencers: A clinical trial

BackgroundFencing is a combat sport, which depends of lower limbs muscular strength and neuromuscular function. Because of that, approximately half of all injuries occur in lower limbs, especially in ankle. Thus, the objective of this study was to verify the influence of a twelve-week proprioceptive training program on ankle muscular strength and muscular balance in fencers.MethodsThe study was a clinical trial, with 19 fencing athletes from 14 to 35-year-old. The main outcome was ankle invertors, evertors, plantiflexors and dorsiflexors muscular strength and ankle muscle balance. The study was performed in six stages: familiarization of muscular strength test in isokinetic dynamometer; pre-intervention; intervention; post-intervention; three- and six-months follow-up. At pre-intervention stage, the muscular strength was evaluated. At intervention stage, the athletes performed 12-week proprioceptive training program, three times a week. At post-intervention, three- and the six-months follow-ups, same pre-intervention test was performed.ResultsThe proprioceptive training improved front leg ankle dorsiflexor strength at three- and six-months follow-ups compared to pre-intervention. Furthermore, training increased the front leg dorsiflexors/plantiflexors conventional ratio at three- and six-months follow-ups compared to pre-intervention; and evertors/invertors conventional ratio at three-months follow-up compared to pre-intervention; and evertors/invertors functional ratio at post-intervention and three- and six-months follow-ups compared to pre-intervention.ConclusionsThe improvement and/or maintenance of ankle muscle strength occurred in intervention group seems to be due to stimulus provided by proprioceptive training, with ankle dorsiflexors being the most stimulated group.     

Effects of applied swan pilates motions on upper body muscle activities

BackgroundThere have been very few studies involving swan motion during pilates exercises, and there is also insufficient scientific evidence to support the fact that Pilates swan motion strengthens specific muscles.ObjectivesFirstly, the purpose of this study was to evaluate the effect of 5 types Pilates swan motion (swan basic (SB), swan push-up (SP), swan holding posture (SH), form roller-based swan (SF), and circle-based swan (SC)) on muscle activity of deltoideus p. acromialis (DA), infraspinatus (IP), trapezius (TP), latissimus dorsi (LD), and erector spinae (ES). Secondly, the purpose of this study was to suggest an effective Pilates swan motion for strengthening muscle strength of each targeted muscle.MethodsTwenty-four healthy men in their 20s participated and all participants were measured muscle activity in DA, IP, TP, LD, and ES muscles by electromyography (EMG) during 5 Pilates swan motions (SB, SP, SH, SF, & SC). The measured values were expressed as relative voluntary contraction (%RVC) values based on the SB.ResultsThe %RVC values representing the muscle activity of DA and TP were significantly higher in SH and SP than in SC, SF, and SB (p < .001). The %RVC values of IP and LD were significantly higher in SH and SC than in SF, SP, and SB (p < .001). The %RVC value of ES was were significantly higher in SH than in SP, SC, SF, and SB (p < .001).ConclusionThe application of SP, SC, and SH Pilates swan motion is an effective method to activate the back muscles of the trunk.     

虚拟现实技术对弱视儿童视功能的影响

目的探讨虚拟现实技术在弱视儿童视功能检查与治疗中的临床效果。方法选取医院2019年5月—2020年3月经检查收治的100例弱视患儿(200只眼)为研究对象,按照基础资料组间均衡可比的原则分为对照组和观察组,各组50例(100眼)。对照组实施国际标准视力表进行常规远近视力检查及传统治疗方法,观察组在对照组基础上实施虚拟现实技术,比较两组患儿治疗后视功能水平。结果治疗后观察组患儿在同时视功能方面与对照组差异无统计学意义(P>0.05);观察组在融合、立体视功能、动态立体视功能方面明显优于对照组,差异有统计学意义(P<0.05)。结论对弱视患儿视功能检查与治疗过程采用虚拟现实技术,可有效提升检查及治疗效果,改善视功能。     

不同干燥工艺对鱼腥草挥发油的影响研究

目的研究不同干燥工艺对大别山鱼腥草挥发油的影响。方法分别用低温烘干(50℃)、晒干、阴干的干燥方式处理新鲜的鱼腥草,挥发油提取器提取挥发油,采用GC-MS检测分析。结果阴干、晒干、烘干鱼腥草中的挥发油分别鉴定出43、37和14种。结论晒干和低温烘干方式均会影响鱼腥草挥发油的组成,但对总体积影响不显著。     

Identification of potential inhibitors of Zika virus NS5 RNA-dependent RNA polymerase through virtual screening and molecular dynamic simulations

Zika virus (ZIKV) is one of the mosquito borne flavivirus with several outbreaks in past few years in tropical and subtropical regions. The non-structural proteins of flaviviruses are suitable active targets for inhibitory drugs due to their role in pathogenicity. In ZIKV, the non-structural protein 5 (NS5) RNA-Dependent RNA polymerase replicates its genome. Here we have performed virtual screening to identify suitable ligands that can potentially halt the ZIKV NS5 RNA dependent RNA polymerase (RdRp). During this process, we searched and screened a library of ligands against ZIKV NS5 RdRp. The selected ligands with significant binding energy and ligand-receptor interactions were further processed. Among the selected docked conformations, top five was further optimized at atomic level using molecular dynamic simulations followed by binding free energy calculations. The interactions of ligands with the target structure of ZIKV RdRp revealed that they form strong bonds within the active sites of the receptor molecule. The efficacy of these drugs against ZIKV can be further analyzed through in-vitro and in-vivo studies.     

L型钙通道介导垂体腺苷酸环化酶激活肽38对大鼠胰岛素分泌的促进作用及其机制研究

目的研究垂体腺苷酸环化酶激活肽38(PACAP38)对大鼠胰岛素分泌的影响及其机制。方法 (1)将大鼠胰岛和胰岛细胞分为4组:正常组(2.8 mmol·L^-1葡萄糖)、模型组(8.3 mmol·L^-1葡萄糖)和低,高2个剂量实验组(模型组+1,10 nmol·L^-1 PACAP38),测定不同干预下的胰岛素分泌量。(2)将大鼠胰岛和胰岛细胞分为5组:正常组、模型组、高剂量实验组、阿折地平(L型钙通道阻滞药)组(模型组+0.1μmol·L^-1阿折地平)和联合组(阿折地平组+高剂量实验组),用胰岛素分泌实验和钙成像技术分别检测阿折地平干预下胰岛素分泌量和β细胞内Ca^2+浓度(F-F0值)水平。结果 (1)正常组、模型组和低、高2个剂量实验组的胰岛素分泌量分别为(86.74±4.05),(165.63±5.26),(175.03±5.21)和(209.28±4.13)μu·mL^-1,模型组与正常组相比,胰岛素分泌量明显增加,差异有统计学意义(P<0.01);高剂量实验组与模型组相比,胰岛素分泌显著增加,差异有统计学意义(P<0.05)。(2)正常组、模型组、高剂量实验组、阿折地平组和联合组的胰岛素分泌量分别为(46.93±4.58),(79.11±8.02),(135.65±3.68),(72.78±7.95),(78.51±5.13)μu·mL^-1;这5组的Ca^2+浓度分别为3.00×10^-2±0.12,6.57×10^-2±0.35,1.40×10^-1±0.46,7.71×10^-2±0.42,8.00×10^-2±0.43,上述指标:模型组与正常组比较,差异均有统计学意义(均P<0.01);高剂量实验组与模型组比较,差异均有统计学意义(均P<0.001);联合组与高剂量实验组比较,差异均有统计学意义(均P<0.001);阿折地平与模型组比较,差异均无统计学意义(均P>0.05)。结论 PACAP38通过作用于L型钙通道,使β细胞内Ca^2+浓度升高,最终促进胰岛素分泌。     

Postural stabilization and balance assessment in Charcot–Marie–Tooth 1A subjects

The aim of the present study was to assess postural stabilization skill in adult subjects affected by Charcot–Marie–Tooth disease (CMT) type 1A. For this purpose ground reaction force (GRF) was measured by means of a piezoelectric force platform during the sit-to-stand (STS) movement, until a steady state erect posture was achieved. Specific indexes to quantify Centre of Mass acceleration, both during postural stabilization and during quiet standing, were computed using a mathematical model. Forty-seven CMT1A subjects were recruited for the study, and the control group was formed by forty-one age- and sex-matched healthy subjects.The results show that CMT1A subjects are less stable than controls during the quiet stance. Greater difficulty (high values of Y_inf, the final instability rate) to maintain erect posture appears to be mainly associated with plantar-flexor muscle weakness, rather than to damage of the proprioceptive system. The worst performances shown by CMT1A subjects in the stabilization phase (high values of I, the global index of postural stabilization performance) seem to be associated with reduced muscle strength and the loss of large sensory nerve fibres.Distal muscle weakness appears to affect both postural stabilization and quiet erect posture. The presented protocol and the analysis of postural stabilization parameters provide useful information on CMT1A balance disorders.