BACKGROUND & AIMS: :Irritable bowel syndrome (IBS) and Functional Abdominal Pain (FAP) are among the most commonly reported Functional Gastrointestinal Disorders. Both have been associated with varying autonomic dysregulation. Heart Rate Variability Biofeedback (HRVB) has recently begun to show efficacy in the treatment of both IBS and FAP. The purpose of this multiple clinical replication series was to analyze the clinical outcomes of utilizing HRVB in a clinical setting. Archival data of twenty-seven consecutive pediatric outpatients diagnosed with IBS or FAP who received HRVB were analyzed. Clinical outcomes were self-report and categorized as full or remission with patient satisfaction, or no improvement. Qualitative reports of patient experiences were also noted. Full remission was achieved by 69.2 % and partial remission was achieved by 30.8 % of IBS patients. Full remission was achieved by 63.6 % and partial remission was achieved by 36.4 % of FAP patients. No patients in either group did not improve to a level of patient satisfaction or >50 %. Patient's commonly reported feeling validated in their discomfort as a result of psychophysiological education. Results suggest that HRVB is a promising intervention for pediatric outpatients with IBS or FAP. Randomized controlled trials are necessary to accurately determine clinical efficacy of HRVB in the treatment of IBS and FAP.

背景与目标： 肠易激综合症（IBS）和功能性腹痛（FAP）是最常报告的功能性胃肠道疾病。两者都与自主神经调节异常有关。心率变异性生物反馈（HRVB）最近已开始显示出对IBS和FAP的治疗功效。这个多重临床复制系列的目的是分析在临床环境中使用HRVB的临床结果。分析了连续27例接受HRVB诊断为IBS或FAP的儿科门诊患者的档案数据。临床结果为自我报告，归类为完全或缓解，患者满意，或无改善。还记录了患者经历的定性报告。 IBS患者的完全缓解率为69.2％，部分缓解的率为30.8％。 FAP患者的完全缓解率为63.6％，部分缓解的率为36.4％。两组中的患者均未达到患者满意度或> 50％的水平。通过心理生理学教育，患者普遍报告的不适感得到了证实。结果表明，HRVB对于有IBS或FAP的小儿门诊患者是一种有前途的干预措施。为了准确确定HRVB在IBS和FAP治疗中的临床疗效，必须进行随机对照试验。

BACKGROUND & AIMS: OBJECTIVE:To examine the correlation between motor impairment, aerobic capacity and HRV parameters in patients who had recently had an ischemic stroke. DESIGN:Thirty-nine patients, after a first CVA. MEASUREMENTS:motor performance (measured by the Motor Assessment Scale (MAS)), aerobic capacity (measured by Heart Rate (HR) at maximal effort and maximal workload (MWL) at graded stress test), both tested two weeks and three-month post event. Heart Rate Variability (HRV) parameters included time domain (ms) and power spectrum (ms(2)) were tested up to two weeks post event. RESULTS:HRV parameters correlated positively with motor performance and aerobic capacity two weeks (MAS: r(p) = 0.47, p < 0.01, maximal workload: r(p) = 0.26, P < 0.05) and three-month (MAS: r(p) = 0.41, p < 0.01, maximal workload: r(p) = 0.20, not significant) post-stroke. CONCLUSIONS:HRV in the acute phase of stroke have positive connection to motor performance and aerobic capacity two weeks post event, and may have a prognostic value to assess motor ability three-month post the event.

背景与目标： 目的：探讨最近患有缺血性中风的患者的运动障碍，有氧运动能力和HRV参数之间的相关性。
设计：39例患者，首次接受CVA后。
测量：运动能力（通过运动评估量表（MAS）测量），有氧运动能力（通过最大压力下的心率（HR）和分级压力测试下最大工作量（MWL）测量），均在术后两周和三个月内进行测试事件。事件发生后最多两周对包括时域（ms）和功率谱（ms（2））在内的心率变异性（HRV）参数进行了测试。
结果：HRV参数与运动能力和有氧运动能力两周呈正相关（MAS：r（p）= 0.47，p <0.01，最大工作量：r（p）= 0.26，P <0.05）和三个月（MAS：r （p）= 0.41，p <0.01，最大工作量：r（p）= 0.20，不显着）。
结论：中风急性期的HRV与事件后两周的运动表现和有氧运动能力呈正相关，可能在事件后三个月评估运动能力的预后价值。

BACKGROUND & AIMS: PURPOSE:Hypercapnia increases minute ventilation (V’E) with little effect on heart rate (HR), whereas hypoxia may increase HR without affecting V’E. However, the effects of hypercapnia and hypoxia on both heart rate variability(HRV) and the clustering of heart beats during spontaneous breathing (respiratory sinus arrhythmia – RSA), are not clear. METHODS:In this study, 10 human volunteers breathed room air (RA), hypercapnic (5% CO2) or hypoxic (10%O2) gas mixtures, each for 6 min, while resting supine. ECG, mean arterial pressure (MAP), ventilatory flow, inhaled and exhaled fractions of CO2 and O2, were recorded throughout. RESULTS:Both V’E and MAP increased with 5%CO2, with no change in HR. Hypoxia did not change ventilation but increased HR. High frequency components of HRV, and the relative proportion of heart beats occurring during inhalation increased with 5% CO2, but neither changed with 10% O2. CONCLUSION:Increased RSA concomitant with increased MAP suggests RSA – vagal dissociation with hypercapnia. Elevated heart rate with acute hypoxia with no change in either frequency components of HRV or the distribution of heart beats during ventilation, suggested that clustering of heart beats may not be a mechanism to improve ventilation-perfusion matching during hypoxia.

背景与目标： 目的：高碳酸血症会增加分钟通气量（V’E），而对心率（HR）的影响很小，而低氧可能会增加HR而不会影响V’E。然而，高碳酸血症和低氧对自发性呼吸（呼吸窦性心律不齐– RSA）期间心率变异性（HRV）和心跳聚集的影响尚不清楚。
方法：在这项研究中，10名人类志愿者在仰卧休息时呼吸了室内空气（RA），高碳酸血症（5％CO2）或低氧（10％O2）混合气体，每次持续6分钟。整个记录心电图，平均动脉压（MAP），通气量，吸入和呼出的CO2和O2分数。
结果：V'E和MAP均随5％CO2的增加而增加，而HR不变。缺氧并没有改变通气，但增加了心率。 HRV的高频成分以及在吸入过程中发生的心跳的相对比例在5％CO2的情况下增加，但在10％O2的情况下都没有变化。
结论：RSA增加伴有MAP升高提示RSA –迷走神经脱离与高碳酸血症。急性缺氧时心率升高，HRV的频率成分或通气期间心跳的分布均无变化，提示心律聚集可能不是改善低氧时通气-灌注匹配的机制。

BACKGROUND & AIMS: :To assess risk factors of recurrent bronchial obstruction and allergic sensitization 3 years after an episode of acute bronchiolitis, whether after ambulatory care treatment or hospitalization. A monocentric prospective longitudinal study including infants aged under 1 year with acute bronchiolitis was performed, with clinical (severity score), biological (serum Krebs von den Lungen 6 antigen), and viral (14 virus by naso-pharyngeal suction detection) assessments. Follow-up included a quaterly telephone interview, and a final clinical examination at 3 years. Biological markers of atopy were also measured in peripheral blood, including specific IgEs towards aero- and food allergens. Complete data were available for 154 children. 46.8% of them had recurrent wheezing (RW). No difference was found according to initial severity, care at home or in the hospital, respiratory virus involved, or existence of co-infection. A familial history of atopy was identified as a risk factor for recurrent bronchial obstruction (60% for RW infants versus 39%, P = 0.02), as living in an apartment (35% versus 15%, P = 0.002). 18.6% of the infants were sensitized, with 48.1% of them sensitized to aeroallergens and 81.5% to food allergens. Multivariate analysis confirmed that a familial history of atopy (P = 0.02) and initial co-infection RSV-hRV (P = 0.02) were correlated with the risk of sensitization to aeroallergens at 3 years. Familial history of atopy and RSV-hRV co-infection are risk factors for recurrent bronchial obstruction and sensitization.

背景与目标： ：评估急性细支气管炎发作后3年（无论是在非卧床护理治疗后还是住院后）复发性支气管阻塞和过敏致敏的危险因素。进行了一项单中心前瞻性纵向研究，包括1岁以下的急性毛细支气管炎婴儿，并进行了临床（严重性评分），生物学（血清Krebs von den Lungen 6抗原）和病毒（鼻咽抽吸检测为14病毒）评估。随访包括季度电话访谈和3年期的最终临床检查。还测量了外周血中特应性的生物学标记，包括针对航空和食物过敏原的特异性IgE。有154名儿童的完整数据。他们中有46.8％患有反复性喘息（RW）。根据最初的严重程度，在家中或医院中的护理，所涉及的呼吸道病毒或是否存在合并感染，均未发现差异。特应性家族病史被确定为复发性支气管阻塞的危险因素（RW婴儿为60％，而39％，P = 0.02），以及居住在公寓中（35％对15％，P = 0.002）。有18.6％的婴儿过敏，其中48.1％的婴儿对空气过敏原敏感，81.5％的食物对过敏原敏感。多变量分析证实，特应性家族史（P = 0.02）和初次合并感染RSV-hRV（P = 0.02）与3年时对气敏原致敏的风险有关。特应性家族病史和RSV-hRV合并感染是复发性支气管阻塞和致敏的危险因素。

BACKGROUND & AIMS: PURPOSE:We analyzed heart rate variability (HRV) taken by ECG and photoplethysmography (PPG) to assess their agreement. We also analyzed the sensitivity and specificity of PPG to identify subjects with low HRV as an example of its potential use for clinical applications. METHODS:The HRV parameters: mean heart rate (HR), amplitude, and ratio of heart rate oscillation (E-I difference, E/I ratio), RMSSD, SDNN, and Power LF, were measured during 1-min deep breathing tests (DBT) in 343 individuals, followed by a 5-min short-term HRV (s-HRV), where the HRV parameters: HR, SD1, SD2, SDNN, Stress Index, Power HF, Power LF, Power VLF, and Total Power, were determined as well. Parameters were compared through correlation analysis and agreement analysis by Bland-Altman plots. RESULTS:PPG derived parameters HR and SD2 in s-HRV showed better agreement than SD1, Power HF, and stress index, whereas in DBT HR, E/I ratio and SDNN were superior to Power LF and RMSSD. DBT yielded stronger agreement than s-HRV. A slight overestimation of PPG HRV over HCG HRV was found. HR, Total Power, and SD2 in the s-HRV, HR, Power LF, and SDNN in the DBT showed high sensitivity and specificity to detect individuals with poor HRV. Cutoff percentiles are given for the future development of PPG-based devices. CONCLUSION:HRV measured by PPG shows good agreement with ECG HRV when appropriate parameters are used, and PPG-based devices can be employed as an easy screening tool to detect individuals with poor HRV, especially in the 1-min DBT test.

背景与目标： 目的：我们分析了心电图和光电容积描记法（PPG）测得的心率变异性（HRV），以评估其一致性。我们还分析了PPG的敏感性和特异性，以鉴定低HRV的受试者，作为其在临床应用中潜在用途的一个例子。
方法：在1分钟的深呼吸测试（DBT）中测量了HRV参数：平均心率（HR），幅度和心率振荡比（EI差，E / I比），RMSSD，SDNN和Power LF ）中的343个人，然后是5分钟的短期HRV（s-HRV），其中的HRV参数为：HR，SD1，SD2，SDNN，压力指数，功率HF，功率LF，功率VLF和总功率，也被确定。通过Bland-Altman图通过相关分析和一致性分析比较参数。
结果：s-HRV中PPG导出的参数HR和SD2显示出比SD1，Power HF和应力指数更好的一致性，而在DBT HR中，E / I比和SDNN优于Power LF和RMSSD。 DBT产生了比s-HRV更强的一致性。发现PPG HRV略高于HCG HRV。 s-HRV中的HR，总功率和SD2，DBT中的HR，功率LF和SDNN对检测HRV较差的个体显示出高灵敏度和特异性。为基于PPG的设备的未来开发提供了截止百分位数。
结论：当使用适当的参数时，PPG测量的HRV与ECG HRV显示出良好的一致性，并且基于PPG的设备可以用作检测HRV较差的个体的简便筛查工具，尤其是在1分钟DBT测试中。

BACKGROUND & AIMS: BACKGROUND:Ultra-short-term heart rate variability (HRV) analysis (< 5 min) has been extensively growing in the field of exercise performance for autonomic assessment. However, the validation of ultra-short-term HRV was unclear in the recovery period of exercise. This study aimed to elucidate the agreement between ultra-short-term HRV (0-30 s, 0-1 min, 0-2 min, 0-3 min, 0-4 min) and standard short-term HRV (5 min) and to explore the optimal recording duration under rest and post-exercise conditions. METHODS:69 participants were recruited to perform physical exercise on a treadmill with an intensity of 6 km/h, 9 km/h and 12 km/h, independently. The standard deviation of RR-interval (SDNN) and root mean square of successive differences of RR-intervals (RMSSD) were calculated by using ultra-short periods and standard period at rest condition (Pre-E) and three post-exercise trials, i.e., Post-E1, Post-E2 and Post-E3, respectively. One-way ANOVA with repeated-measures and Cohen's d statistics were conducted, and Bland-Altman analysis and interclass correlation coefficients (ICC) were used to assess the levels of agreement. RESULTS:For SDNN and RMSSD, the results of agreement analysis at rest condition were different from those at post-exercise. At Pre-E, SDNN and RMSSD were reliable for ultra-short-term HRV analysis at all ultra-short periods, i.e., 0-30 s, 0-1 min, 0-2 min, 0-3 min and 0-4 min, with most ICCs greater than 0.9 and Cohen's d showing trivial differences (Cohen's d = 0.024-0.117). However, at post-exercise, SDNN0-30s, SDNN0-1min, RMSSD0-30s and RMSSD0-1min showed significant differences with SDNN5min and RMSSD5min, respectively (p < 0.01), and the ICCs was not perfect (< 0.9). HRV analysis with time duration longer than 2 min showed nearly perfect reliability in all post-exercise trials, with trivial differences (Cohen's d = -0.003-0.110) and perfect ICCs (ICCs = 0.916-0.998). Furthermore, the limits of the agreement became tighter as the period duration increased in Bland-Altman plots. CONCLUSIONS:This study demonstrated that ultra-short-term HRV analysis was a good surrogate of standard HRV time-domain measures to reflect the autonomic regulation at rest and post-exercise. Specifically, ultra-short-term HRV0-30s or HRV0-1min was recommended at rest condition, whereas longer than 2 min recording period was reliable to obtain SDNN and RMSSD for the accuracy of HRV analysis.

背景与目标： 背景：超短期心率变异性（HRV）分析（<5分钟）在用于自主评估的运动表现领域已得到广泛发展。但是，在运动恢复期间，超短期HRV的有效性尚不清楚。本研究旨在阐明超短期HRV（0-30s，0-1min，0-2min，0-3min，0-4min）与标准短期HRV（5min）之间的一致性并探索在休息和运动后条件下的最佳录音时间。
方法：招募了69名参与者，分别在6km / h，9km / h和12km / h的跑步机上进行体育锻炼。 RR间隔的标准偏差（SDNN）和RR间隔的连续差的均方根（RMSSD）是通过使用超短周期和静止状态下的标准周期（Pre-E）以及三个运动后试验来计算的，即分别为Post-E1，Post-E2和Post-E3。进行了带有重复测量的单向方差分析和Cohen d统计，并使用了Bland-Altman分析和类间相关系数（ICC）来评估一致性水平。
结果：对于SDNN和RMSSD，静止状态下的协议分析结果与运动后的结果不同。在Pre-E上，SDNN和RMSSD在所有超短周期（即0-30s，0-1min，0-2min，0-3min和0-4）的超短期HRV分析中都是可靠的min，大多数ICC大于0.9，Cohen d表现出微不足道的差异（Cohen d = 0.024-0.117）。然而，运动后，SDNN0-30s，SDNN0-1min，RMSSD0-30s和RMSSD0-1min分别与SDNN5min和RMSSD5min表现出显着差异（p <0.01），而ICC并不完美（<0.9）。持续时间超过2分钟的HRV分析显示，在所有运动后试验中，可靠性几乎都是完美的，差异不大（Cohen d = -0.003-0.110）和完美的ICC（ICC = 0.916-0.998）。此外，随着Bland-Altman地块中时间段的增加，协议的限制越来越严格。
结论：这项研究表明，超短期HRV分析是标准HRV时域测量的良好替代，可反映静息和运动后的自主神经调节。具体而言，建议在静止状态下使用超短期HRV0-30s或HRV0-1min，而对于HRV分析的准确性而言，超过2分钟的记录时间对于获得SDNN和RMSSD是可靠的。

BACKGROUND & AIMS: OBJECTIVES:The aim of the study was to verify whether simultaneous responses from the muscular and circulatory system occur in the driver's body under simulated conditions of a crash threat. MATERIALS AND METHODS:The study was carried out in a passenger car driving simulator. The crash was included in the driving test scenario developed in an urban setting. In the group of 22 young male subjects, two physiological signals - ECG and EMG were continuously recorded. The length of the RR interval in the ECG signal was assessed. A HRV analysis was performed in the time and frequency domains for 1-minute record segments at rest (seated position), during undisturbed driving as well as during and several minutes after the crash. For the left and right side muscles: m. trapezius (TR) and m. flexor digitorum superficialis (FDS), the EMG signal amplitude was determined. The percentage of maximal voluntary contraction (MVC) was compared during driving and during the crash. RESULTS:As for the ECG signal, it was found that in most of the drivers changes occurred in the parameter values reflecting HRV in the time domain. Significant changes were noted in the mean length of RR intervals (mRR). As for the EMG signal, the changes in the amplitude concerned the signal recorded from the FDS muscle. The changes in ECG and EMG were simultaneous in half of the cases. CONCLUSION:Such parameters as mRR (ECG signal) and FDS-L amplitude (EMG signal) were the responses to accident risk. Under simulated conditions, responses from the circulatory and musculoskeletal systems are not always simultaneous. The results indicate that a more complete driver's response to a crash in road traffic is obtained based on parallel recording of two physiological signals (ECG and EMG).

背景与目标： 目的：该研究的目的是验证在模拟碰撞危险条件下，驾驶员体内是否同时发生了肌肉和循环系统的同时反应。
材料与方法：该研究在乘用车驾驶模拟器中进行。该事故包括在城市环境中开发的驾驶测试方案中。在22名年轻男性受试者的组中，连续记录了两种生理信号-ECG和EMG。评估心电图信号中RR间隔的长度。在时域和频域中，在静止（坐姿），无扰动驾驶以及碰撞过程中和碰撞后的几分钟内，对时长为1分钟的记录段进行了HRV分析。对于左侧和右侧肌肉：m。斜方肌（TR）和m。浅指屈肌（FDS），确定肌电信号幅度。在驾驶过程中和碰撞期间比较了最大自愿收缩（MVC）的百分比。
结果：关于ECG信号，发现在大多数驱动程序中，时域中反映HRV的参数值发生了变化。注意到RR间隔的平均长度（mRR）有显着变化。对于EMG信号，振幅的变化与从FDS肌肉记录的信号有关。在一半的病例中，心电图和肌电图的变化是同时发生的。
结论：mRR（ECG信号）和FDS-L振幅（EMG信号）等参数是对事故风险的响应。在模拟条件下，循环系统和肌肉骨骼系统的响应并不总是同时发生的。结果表明，基于两个生理信号（ECG和EMG）的并行记录，可以获得驾驶员对道路交通事故更完整的响应。

BACKGROUND & AIMS: OBJECTIVE:This paper proposes an approach to better estimate the sympathovagal balance (SB) and the respiratory sinus arrhythmia (RSA) after separating respiratory influences from the heart rate (HR). METHODS:The separation is performed using orthogonal subspace projections and the approach is first tested using simulated HR and respiratory signals with different spectral properties. Then, RSA and SB are estimated during autonomic blockade and stress using the proposed approach and the classical heart rate variability (HRV) analysis. Both real- and ECG-derived respiration (EDR) are used and the reliability of the EDR is evaluated. RESULTS:Mean absolute percentage errors lower than [Formula: see text] were obtained after removing previously known respiratory signals from simulated HR. The proposed indices were able to improve the quantification of SB during autonomic withdrawal. In the stress data, differences ( ) among relaxed and stressful phases were found with the proposed approach, using both the real respiration and the EDR, but they disappeared when using the classical HRV. CONCLUSION:A better assessment of the autonomic nervous system' response to pharmacological blockade and stress can be achieved after removing respiratory influences from HR, and this can be done using either the real respiration or the EDR. SIGNIFICANCE:This work can be used to better identify vagal withdrawal and increased sympathetic activation when the classical HRV analysis fails due to the respiratory influences on HR. Furthermore, it can be computed using only the ECG, which is an advantage when developing wearable systems with limited number of sensors.

背景与目标： 目的：本文提出了一种在将呼吸影响与心率（HR）分开后，更好地估计交感迷走平衡（SB）和呼吸窦性心律不齐（RSA）的方法。
方法：使用正交子空间投影进行分离，并且首先使用模拟的HR和具有不同光谱特性的呼吸信号测试该方法。然后，使用拟议的方法和经典心率变异性（HRV）分析，在自主神经阻滞和压力期间估算RSA和SB。真实呼吸和心电衍生呼吸（EDR）均被使用，并且评估了EDR的可靠性。
结果：从模拟心率中去除先前已知的呼吸信号后，获得的平均绝对百分比误差低于[公式：参见文本]。拟议的指标能够在自主停药期间改善SB的定量。在压力数据中，使用实际呼吸和EDR，通过所提出的方法发现了放松阶段和压力阶段之间的差异（），但是当使用经典HRV时，它们消失了。
结论：去除HR的呼吸影响后，可以更好地评估植物神经系统对药理学阻断和压力的反应，这可以通过实际呼吸或EDR来完成。
意义：当经典的HRV分析由于呼吸对HR的影响而失败时，这项工作可用于更好地识别迷走神经退缩和增加的交感神经激活。此外，可以仅使用ECG进行计算，这在开发传感器数量有限的可穿戴系统时是一个优势。

BACKGROUND & AIMS: :The purpose of the present work was to compare daily variations of heart rate variability (HRV) parameters between controlled breathing (CB) and spontaneous breathing (SB) sessions during a longitudinal follow-up of athletes. HRV measurements were performed daily on 10 healthy male runners for 21 consecutive days. The signals were recorded during two successive randomised 5-minutes sessions. One session was performed in CB and the other in SB. The results showed significant differences between the two respiration methods in the temporal, nonlinear and frequency domains. However, significant correlations were observed between CB and SB (higher than 0.70 for RMSSD and SD1), demonstrating that during a longitudinal follow-up, these markers provide the same HRV variations regardless of breathing pattern. By contrast, independent day-to-day variations were observed with HF and LF/HF frequency markers, indicating no significant relationship between SB and CB data over time. Therefore, we consider that SB and CB may be used for HRV longitudinal follow-ups only for temporal and nonlinear markers. Indeed, the same daily increases and decreases were observed whatever the breathing method employed. Conversely, frequency markers did not provide the same variations between SB and CB and we propose that these indicators are not reliable enough to be used for day-to-day HRV monitoring.

背景与目标： ：本研究的目的是在运动员的纵向随访过程中比较控制呼吸（CB）和自发呼吸（SB）期间心率变异性（HRV）参数的每日变化。每天对10名健康的男性跑步者进行连续21天的HRV测量。在两个连续的随机5分钟会话中记录信号。一次会议在CB中进行，另一次在SB中进行。结果显示两种呼吸方法在时域，非线性和频域上存在显着差异。但是，在CB和SB之间观察到显着相关性（RMSSD和SD1高于0.70），表明在纵向随访期间，这些标志物提供了相同的HRV变化，而与呼吸方式无关。相比之下，使用HF和LF / HF频率标记观察到了独立的每日变化，表明SB和CB数据之间没有随时间的显着关系。因此，我们认为SB和CB仅可用于时间和非线性标记物用于HRV纵向随访。实际上，无论采用哪种呼吸方法，每天都观察到相同的每日增加和减少。相反，频率标记在SB和CB之间没有提供相同的变化，我们建议这些指标不够可靠，无法用于日常HRV监测。

BACKGROUND & AIMS: :The aim of this study was to investigate the effects of walking training with and without blood flow restriction (BFR) on heart rate (HR) and heart rate variability (HRV) kinetics and HRV recovery. Twenty-one men (53.5±3.2 years; 82.4±13.5 kg; 168.5±7.2 cm) were randomly assigned to two training groups: walk training group with (BFR-W; n=11) and without (NOR-W; n=10) BFR. Before and after training, all subjects underwent body composition evaluation, incremental test, and one constant load test. Walking training was performed 3 times/week, during 6 weeks. Each session was composed by 5 sets of 3-min walking and 1-min rest between the sets. All parameters of HR on- and off-kinetics and RMSSD15 0 parameter of HRV on-kinetics were improved for BFR-W group after training (p<0.05), with an interaction effect for HR on-kinetics parameters and RMSSD15 0 parameter (p<0.05). Also, parameters of time and frequency domain of HRV recovery were also improved in BFR-W after training (p<0.05), with no interaction effect (p>0.05). Additionally, in BFR-W group, RMSSD60s values were improved in some moments after training (p<0.05). Therefore, this study demonstrates that a 6-week walking training with BFR improved cardiac autonomic responses on the onset and recovery of exercise.

背景与目标： ：这项研究的目的是研究有无血流限制（BFR）的步行训练对心率（HR）和心率变异性（HRV）动力学及HRV恢复的影响。将21名男性（53.5±3.2岁; 82.4±13.5 kg; 168.5±7.2 cm）随机分为两个训练组：有（BFR-W; n = 11）和没有（NOR-W; n = 10）BFR。训练前后，所有受试者均接受身体成分评估，增量测试和一项恒定负荷测试。在6周内，每周进行3次步行训练。每个阶段由5组3分钟的步行和1分钟的休息时间组成。训练后BFR-W组的HR动力学和非动力学的所有参数以及HRV动力学的RMSSD15 0参数均得到改善（p <0.05），并且HR动力学参数和RMSSD15 0参数（p <0.05）。此外，训练后的BFR-W中HRV恢复的时域和频域参数也得到了改善（p <0.05），没有相互作用（p> 0.05）。此外，在BFR-W组中，训练后的某些时候RMSSD60s值有所改善（p <0.05）。因此，这项研究表明，使用BFR进行的6周步行训练可改善运动开始和恢复时的心脏自主神经反应。

BACKGROUND & AIMS: BACKGROUND AND OBJECTIVE:Paroxysmal Atrial Fibrillation (PAF) is one of the most common major cardiac arrhythmia. Unless treated timely, PAF might transform into permanent Atrial Fibrillation leading to a high rate of morbidity and mortality. Therefore, increasing attention has been directed towards prediction of PAF, to enable early detection and prevent further progression of the disease. Notwithstanding the pharmacological and electrical treatments, a validated method to predict the onset of PAF is yet to be developed. We aim to address this issue through integrating classical and modern methods. METHODS:To increase the predictivity, we have made use of a combination of features extracted through linear, time-frequency, and nonlinear analyses performed on heart rate variability. We then apply a novel approach to local feature selection using meticulous methodologies, developed in our previous works, to reduce the dimensionality of the feature space. Subsequently, the Mixture of Experts classification is employed to ensure a precise decision-making on the output of different processes. In the current study, we analyzed 106 signals from 53 pairs of ECG recordings obtained from the standard database called Atrial Fibrillation Prediction Database (AFPDB). Each pair of data contains one 30-min ECG segment that ends just before the onset of PAF event and another 30-min ECG segment at least 45 min distant from the onset. RESULTS:Combining the features that are extracted using both classical and modern analyses was found to be significantly more effective in predicting the onset of PAF, compared to using either analyses independently. Also, the Mixture of Experts classification yielded more precise class discrimination than other well-known classifiers. The performance of the proposed method was evaluated using the Atrial Fibrillation Prediction Database (AFPDB) which led to sensitivity, specificity, and accuracy of 100%, 95.55%, and 98.21% respectively. CONCLUSION:Prediction of PAF has been a matter of clinical and theoretical importance. We demonstrated that utilising an optimized combination of - as opposed to being restricted to - linear, time-frequency, and nonlinear features, along with applying the Mixture of Experts, contribute greatly to an early detection of PAF, thus, the proposed method is shown to be superior to those mentioned in similar studies in the literature.

背景与目标： 背景与目的：阵发性房颤（PAF）是最常见的严重心律不齐之一。除非及时治疗，PAF可能会转变为永久性房颤，从而导致高发病率和死亡率。因此，人们越来越关注PAF的预测，以能够及早发现并预防疾病的进一步发展。尽管进行了药理学和电学治疗，但仍未开发出验证有效的预测PAF发作的方法。我们旨在通过整合古典和现代方法来解决这个问题。
方法：为了提高可预测性，我们利用了通过对心率变异性进行线性，时频和非线性分析而提取的特征的组合。然后，我们使用在我们先前的工作中开发的细致方法，将新颖的方法应用于局部特征选择，以减少特征空间的维数。随后，采用专家混合分类，以确保对不同过程的输出做出准确的决策。在当前的研究中，我们分析了53对心电图记录中的106个信号，这些记录来自称为房颤预测数据库（AFPDB）的标准数据库。每对数据包含一个30分钟的ECG段，该段在PAF事件发作之前结束，另一个30分钟的ECG段在距发作至少45分钟的距离处结束。
结果：与单独使用任何一种分析相比，结合使用经典分析和现代分析所提取的特征，在预测PAF发作方面明显更有效。而且，专家混合分类比其他知名分类器产生了更精确的类区分。使用心房颤动预测数据库（AFPDB）对所提出方法的性能进行了评估，结果数据库的敏感性，特异性和准确性分别为100％，95.55％和98.21％。
结论：PAF的预测已成为临床和理论上的重要问题。我们证明，利用-而不是限于-线性，时频和非线性特征的优化组合，以及应用专家混合，对PAF的早期检测有很大贡献，因此，该方法被展示优于文献中类似研究中提到的那些。

BACKGROUND & AIMS: :Recent laboratory studies have suggested that heart rate variability (HRV) may be an appropriate criterion for training load (TL) quantification. The aim of this study was to validate a novel HRV index that may be used to assess TL in field conditions. Eleven well-trained long-distance male runners performed four exercises of different duration and intensity. TL was evaluated using Foster and Banister methods. In addition, HRV measurements were performed 5 minutes before exercise and 5 and 30 minutes after exercise. We calculated HRV index (TLHRV) based on the ratio between HRV decrease during exercise and HRV increase during recovery. HRV decrease during exercise was strongly correlated with exercise intensity (R = -0.70; p < 0.01) but not with exercise duration or training volume. TLHRV index was correlated with Foster (R = 0.61; p = 0.01) and Banister (R = 0.57; p = 0.01) methods. This study confirms that HRV changes during exercise and recovery phase are affected by both intensity and physiological impact of the exercise. Since the TLHRV formula takes into account the disturbance and the return to homeostatic balance induced by exercise, this new method provides an objective and rational TL index. However, some simplification of the protocol measurement could be envisaged for field use.

背景与目标： ：最近的实验室研究表明，心率变异性（HRV）可能是训练负荷（TL）量化的合适标准。这项研究的目的是验证一种新的HRV指数，该指数可用于评估田间条件下的TL。 11名训练有素的长跑男运动员进行了4次不同持续时间和强度的运动。使用Foster和Banister方法评估TL。另外，在运动前5分钟以及运动后5和30分钟进行HRV测量。我们根据运动过程中HRV下降与恢复过程中HRV上升之间的比率计算HRV指数（TLHRV）。运动期间HRV降低与运动强度密切相关（R = -0.70; p <0.01），但与运动时间或训练量无关。 TLHRV指数与Foster（R = 0.61; p = 0.01）和Banister（R = 0.57; p = 0.01）方法相关。这项研究证实，运动和恢复阶段的HRV变化受运动强度和生理影响的影响。由于TLHRV公式考虑了运动引起的干扰和稳态平衡的恢复，因此该新方法提供了客观合理的TL指数。但是，可以设想一些简化的协议测量以供现场使用。

BACKGROUND & AIMS: :2-Methoxystypandrone, a naphthoquinone, was isolated from a Chinese herb Polygonum cuspidatum by bioassay guided fractionation using HRV 3C-protease assay. It showed an IC(50) value of 4.6 microM and is moderately selective. A new 10-step, total synthesis of 2-methoxystypandrone was accomplished in 45% overall yield using a Diels-Alder approach. Several analogues of this compound were prepared. Isolation, synthesis and HRV 3C-protease structure-activity relationships of these compounds have been described.

背景与目标： 通过使用HRV 3C蛋白酶测定法的生物测定指导分级分离，从中药虎杖中分离出2：2-甲氧基stypandrone（萘醌）。它显示的IC（50）值为4.6 microM，具有中等选择性。使用Diels-Alder方法，新的10步全合成2-甲氧基苯乙烯吡喃酮的总收率为45％。制备了该化合物的几种类似物。已经描述了这些化合物的分离，合成和HRV 3C-蛋白酶结构-活性关系。

BACKGROUND & AIMS: :Rhinovirus infections are the most common cause of viral illness in humans, and there is increasing evidence of their etiological role in severe acute respiratory tract infections (ARTIs). Human rhinoviruses (HRVs) are classified into two species, species A and B, which contain over 100 serotypes, and a recently discovered genetically heterogeneous third species (HRV species C). To investigate their diversity and population turnover, screening for the detection and the genetic characterization of HRV variants in diagnostic respiratory samples was performed by using nested primers for the efficient amplification of the VP4-VP2 region of HRV (and enterovirus) species and serotype identification. HRV species A, B, and C variants were detected in 14%, 1.8%, and 6.8%, respectively, of 456 diagnostic respiratory samples from 345 subjects (6 samples also contained enteroviruses), predominantly among children under age 10 years. HRV species A and B variants were remarkably heterogeneous, with 22 and 6 different serotypes, respectively, detected among 73 positive samples. Similarly, by using a pairwise distance threshold of 0.1, species C variants occurring worldwide were provisionally assigned to 47 different types, of which 15 were present among samples from Edinburgh, United Kingdom. There was a rapid turnover of variants, with only 5 of 43 serotypes detected during both sampling periods. By using divergence thresholds and phylogenetic analysis, several species A and C variants could provisionally be assigned to new types. An initial investigation of the clinical differences between rhinovirus species found HRV species C to be nearly twice as frequently associated with ARTIs than other rhinovirus species, which matches the frequencies of detection of respiratory syncytial virus. The study demonstrates the extraordinary genetic diversity of HRVs, their rapid population turnover, and their extensive involvement in childhood respiratory disease.

背景与目标： 鼻病毒感染是人类最常见的病毒性疾病，越来越多的证据表明它们在严重的急性呼吸道感染（ARTIs）中起病因作用。人类鼻病毒（HRV）分为两种，分别为A和B，包含100多种血清型，以及最近发现的遗传上异源的第三种（HRV物种C）。为了研究它们的多样性和种群更新，使用嵌套引物对HRV（和肠病毒）物种的VP4-VP2区进行有效扩增和血清型鉴定，以筛查诊断性呼吸道样本中HRV变异的检测和遗传特征。在345个受试者的456个诊断性呼吸道样本中检出了HRV的A，B和C变种，分别为14％，1.8％和6.8％（6个样本还包含肠病毒），主要发生在10岁以下的儿童中。 HRV物种A和B变异非常异质，在73个阳性样本中分别检测到22和6种不同的血清型。同样，通过使用成对距离阈值0.1，全球范围内发生的C类变种被临时分配给47种不同类型，其中15种存在于英国爱丁堡的样本中。变异的快速转换，在两个采样期间仅检测到43种血清型中的5种。通过使用差异阈值和系统发育分析，可以将几种物种A和C变体临时分配给新类型。对鼻病毒种类之间临床差异的初步调查发现，HRV种类C与ARTIs的关联频率几乎是其他鼻病毒种类的两倍，这与检测呼吸道合胞病毒的频率相符。这项研究证明了HRV的非同寻常的遗传多样性，其快速的人口流动以及它们广泛参与了儿童呼吸道疾病。

BACKGROUND & AIMS: BACKGROUND:Human Rhinoviruses (HRVs) are well recognized viral pathogens associated with acute respiratory tract illnesses (RTIs) abundant worldwide. Although recent studies have phylogenetically identified the new HRV species (HRV-C), data on molecular epidemiology, genetic diversity, and clinical manifestation have been limited. RESULT:To gain new insight into HRV genetic diversity, we determined the complete coding sequences of putative new members of HRV species C (HRV-CU072 with 1% prevalence) and HRV-B (HRV-CU211) identified from clinical specimens collected from pediatric patients diagnosed with a symptom of acute lower RTI. Complete coding sequence and phylogenetic analysis revealed that the HRV-CU072 strain shared a recent common ancestor with most closely related Chinese strain (N4). Comparative analysis at the protein level showed that HRV-CU072 might accumulate substitutional mutations in structural proteins, as well as nonstructural proteins 3C and 3 D. Comparative analysis of all available HRVs and HEVs indicated that HRV-C contains a relatively high G+C content and is more closely related to HEV-D. This might be correlated to their replication and capability to adapt to the high temperature environment of the human lower respiratory tract. We herein report an infrequently occurring intra-species recombination event in HRV-B species (HRV-CU211) with a crossing over having taken place at the boundary of VP2 and VP3 genes. Moreover, we observed phylogenetic compatibility in all HRV species and suggest that dynamic mechanisms for HRV evolution seem to be related to recombination events. These findings indicated that the elementary units shaping the genetic diversity of HRV-C could be found in the nonstructural 2A and 3D genes. CONCLUSION:This study provides information for understanding HRV genetic diversity and insight into the role of selection pressure and recombination mechanisms influencing HRV evolution.

背景与目标： 背景：人类鼻病毒（HRV）是公认的与世界范围内大量急性呼吸道疾病（RTI）相关的病毒病原体。尽管最近的研究在系统发育上鉴定出了新的HRV种类（HRV-C），但有关分子流行病学，遗传多样性和临床表现的数据仍然有限。
结果：为了获得对HRV遗传多样性的新见解，我们确定了从儿科临床标本中鉴定出的HRV C类推定新成员（HRV-CU072，患病率1％）和HRV-B（HRV-CU211）的完整编码序列。被诊断患有急性下肢RTI症状的患者。完整的编码序列和系统发育分析表明，HRV-CU072菌株与最接近的中国菌株（N4）具有最近的共同祖先。在蛋白质水平上的比较分析表明，HRV-CU072可能会在结构蛋白以及非结构蛋白3C和3D中积累取代突变。对所有可用HRV和HEV的比较分析表明，HRV-C包含相对较高的GC含量，且与HEV-D密切相关。这可能与其复制和适应人类下呼吸道高温环境的能力有关。我们在此报告了在HRV-B物种（HRV-CU211）中很少发生的种内重组事件，并在VP2和VP3基因的边界发生了杂交。此外，我们观察到了所有HRV物种的系统发育相容性，并表明HRV进化的动力学机制似乎与重组事件有关。这些发现表明，可在非结构性2A和3D基因中找到影响HRV-C遗传多样性的基本单位。
结论：本研究为了解HRV遗传多样性提供信息，并深入了解选择压力和重组机制对HRV进化的影响。