The Short‐Term Effect of Occupational Levels of 50 Hz Electromagnetic Field on Human Heart Rate Variability

Previous studies have indicated that there is no consensus on the effects of extremely low‐frequency electromagnetic (ELF‐EMF) exposure on the cardiovascular system. This study aimed to explore the short‐term effect of ELF‐EMF exposure on heart rate (HR) and HR variability (HRV). The sample consisted of 34 healthy males aged 18–27 years. The participants were randomly assigned to the EMF (n = 17) or the Sham group (n = 17). We employed a double‐blind repeated‐measures design consisting of three 5 min experimental periods. The chest region of each individual in the EMF group was exposed to 50 Hz, 28 μT, linear polarized, continuous EMF during the EMF exposure period. HR and HRV data were recorded continuously by using a photoplethysmography sensor. Within‐subject statistical analysis indicated a significant HR deceleration in both the EMF and Sham groups. However, the standard deviation of the NN intervals (SDNN), root mean square of successive differences (RMSSD), low‐frequency (LF), and high‐frequency (HF) powers increased only in the EMF group and remained stable in the Sham group. We also compared the same HRV indices measured during the EMF and Sham periods between the two experimental groups. The between‐subject analysis results demonstrated significantly higher SDNN, RMSSD, LF, and HF values in the EMF group than in the Sham group. The LF/HF ratio did not change significantly within and between groups. On the basis of these results, we concluded that short‐term exposure of the chest region to ELF‐EMF could potentially enhance parasympathetic predominance during the resting condition. Bioelectromagnetics. 2021;42:60–75. © 2020 Bioelectromagnetics Society.     

1950 MHz射频电磁场对SRA01/04细胞周期和凋亡的影响

目的：研究显示射频电磁场与白内障的发生关系密切,为了评价晶状体上皮细胞在射频电磁场诱导的白内障发生中的作 用,本实验探讨了1950 MHz射频电磁场暴露对人眼晶状体上皮细胞株（SRA01/04）细胞周期与凋亡的影响。方法：将处于对数生 长期的SRA01/04 细胞暴露或假暴露于频率为1950 MHz,比吸收率（SAR）为2.79 W/kg 的射频电磁场中,每天暴露1 h,每周暴露 5 天,连续暴露4 周。暴露结束后立即收集细胞,显微镜下观察细胞形态变化,噻唑蓝（MTT）法检测细胞存活力,流式细胞仪 （FCM）检测细胞周期与凋亡。结果：与假辐照组相比,暴露组细胞形态未见明显变化;细胞存活力、细胞周期分布及细胞凋亡率亦 无显著改变（P>0.05）。结论：1950 MHz射频电磁场暴露4 周对SRA01/04 细胞的形态、活力、周期以及凋亡均无明显影响,提示在 本实验条件下1950 MHz 射频电磁场不会诱发白内障的发生。     

1950 MHz射频电磁场对人脐带间充质干细胞增殖和成骨分化的影响研究

目的:间充质干细胞(Mesenchymal stem cells,MSCs)具有广阔的临床应用前景,但由于其体外增殖和定向分化等问题,制约了其进一步应用。本研究拟探讨1950MHz射频电磁场(Radio-frequency electromagnetic fields,RF-EMF)对人脐带间充质干细胞(Human umbilical cord mesenchymal stem cells,hUC-MSCs)增殖和成骨方向分化的影响,以期为MSCs的体外增殖和定向分化提供一条新途径。方法:华通氏胶组织块法分离培养人脐带间充质干细胞,流式细胞仪检测间充质干细胞特异性标志物。选择鉴定后的第3至第6代(P3-P6)hUC-MSCs用于实验。将hUC-MSCs细胞暴露或假暴露于频率为1950 MHz,比吸收率(Specific absorption rate,SAR)分别为0.5,1.0和2.0 W/kg的RF-EMF中,每天暴露1 h(5 min开,10 min关),连续暴露7 d。暴露结束后,流式细胞仪检测细胞周期,免疫荧光检测增殖相关蛋白Ki67表达,连续6天用CCK-8方法检测细胞数。在成骨分化研究中,将P3代的hUC-MSCs随机分为假暴露(sham)组,射频辐射暴露(RF)组,成骨诱导培养基组(Induction medium,OM)和成骨诱导培养基联合射频辐射暴露(OM+RF)组,暴露SAR值为2.0 W/kg,其它参数不变。暴露结束后立即检测细胞的碱性磷酸酶(Alkaline phosphatase,ALP)活性。结果:原代培养的细胞具有MSC典型外观,且表达MSCs特异性表面抗原。与sham组相比,不同SAR值RF暴露后,hUC-MSCs的增殖能力无明显变化,S期细胞比例及Ki67蛋白水平也无显著改变。此外,hUC-MSCs经SAR值为2.0W/kg的RF暴露7 d,与sham组相比其ALP活性无显著变化。与OM组相比,OM+RF组的ALP活性亦无显著改变。结论:华通氏胶组织块法能够培养出纯度较高的间充质干细胞,本实验条件下的1950 MHz射频电磁场对hUC-MSCs的增殖和成骨分化均无显著影响。     

Estimation of Electromagnetic Dosimetric Values from Non-Ionizing Radiofrequency Fields in an Indoor Commercial Airplane Environment

In this article, the impact of topology as well as morphology of a complex indoor environment such as a commercial aircraft in the estimation of dosimetric assessment is presented. By means of an in-house developed deterministic 3D ray-launching code, estimation of electric field amplitude as a function of position for the complete volume of a commercial passenger airplane is obtained. Estimation of electromagnetic field exposure in this environment is challenging, due to the complexity and size of the scenario, as well as to the large metallic content, giving rise to strong multipath components. By performing the calculation with a deterministic technique, the complete scenario can be considered with an optimized balance between accuracy and computational cost. The proposed method can aid in the assessment of electromagnetic dosimetry in the future deployment of embarked wireless systems in commercial aircraft.     

An in vitro study of the effects of exposure to a GSM signal in two human cell lines: monocytic U937 and neuroblastoma SK-N-SH

The use of mobile phones is increasing, which also increases the population's exposure to global system of mobile communications (GSM) signals. Questions of safety and possible biological effects are of concern and to date, remain largely unanswered. In order to examine possible biological effects of a GSM-like signal at a cellular level, we exposed two human cell lines (one of neuronal (SK-N-SH) and the other of monocytoid (U937) origin) to a 900 MHz RF signal, pulsed at 217 Hz, producing a specific absorption rate (SAR) of 0.2 W/kg. Putative effects were assessed by comparing radiofrequency-exposed cells to sham-exposed cells using a variety of assay techniques. For the cell line SK-N-SH, effects were specifically assessed by gene microarray, followed by real-time PCR of the genes of interest, Western blot analysis was used to measure heat shock protein levels, and flow cytometry to measure cell cycle distributions and apoptosis. Effects of radiofrequency on the cell line U937 were assessed by cell viability and cell cycle analysis. From our study of these two cell lines, we found no significant difference between sham-exposed versus radiofrequency-exposed cells in any of the assays or conditions examined.     

Output power distributions of terminals in a 3G mobile communication network

The objective of this study was to examine the distribution of the output power of mobile phones and other terminals connected to a 3G network in Sweden. It is well known that 3G terminals can operate with very low output power, particularly for voice calls. Measurements of terminal output power were conducted in the Swedish TeliaSonera 3G network in November 2008 by recording network statistics. In the analysis, discrimination was made between rural, suburban, urban, and dedicated indoor networks. In addition, information about terminal output power was possible to collect separately for voice and data traffic. Information from six different Radio Network Controllers (RNCs) was collected during at least 1 week. In total, more than 800000 h of voice calls were collected and in addition to that a substantial amount of data traffic. The average terminal output power for 3G voice calls was below 1 mW for any environment including rural, urban, and dedicated indoor networks. This is <1% of the maximum available output power. For data applications the average output power was about 6–8 dB higher than for voice calls. For rural areas the output power was about 2 dB higher, on average, than in urban areas. Bioelectromagnetics 33:320–325, 2012. © 2011 Wiley Periodicals, Inc.     

2型糖尿病患者心率变异性时域及频域参数与颈动脉粥样硬化的相关性分析

摘要 目的：探讨2型糖尿病患者心率变异性（HRV）时域及频域参数与颈动脉粥样硬化（CAS）患病风险的相关性。方法：根据纳入与排除标准共收集2019年7月至2021年8月上海交通大学医学院附属第九人民医院内分泌代谢科住院的377例2型糖尿病患者的临床资料,并通过3分钟的心电图记录HRV时域[R-R间隔的标准差（SDNN）、相邻R-R间隔差值的均方根（RMSSD）、相邻R-R间隔差值>50 ms的数目占所有R-R间隔总数百分比（PNN50）]和频域[低频功率（LF）、高频功率（HF）、LF/HF、总功率（TP）]参数。根据颈动脉超声有无斑块形成分为无CAS组和CAS组,分析其与HRV各参数的关系。结果：与无CAS组相比,CAS组年龄、心血管疾病、体质量指数（BMI）、糖化血红蛋白A1c（HbA1C）、甘油三酯（TG）水平明显升高,舒张压（DBP）、空腹血糖（FPG）水平降低,差异具有统计学意义（P＜0.05）。CAS组大多数HRV参数低于无CAS组,包括SDNN、RMSSD、PNN50、LF、LF/HF、TP,差异有统计学意义（P＜0.05或P＜0.01）。SDNN与年龄、病程、心血管疾病、饮酒呈负相关（P＜0.05或P＜0.01）;RMSSD与病程、饮酒呈负相关（P＜0.05或P＜0.01）;PNN50与病程呈负相关（P＜0.05）;LF与年龄、病程、心血管疾病呈负相关,与DBP、低密度脂蛋白（LDL）呈正相关（P＜0.05或P＜0.01）;HF与年龄、病程呈负相关,与LDL呈正相关（P＜0.05或P＜0.01）;LF/HF与年龄、心血管疾病、TG呈负相关（P＜0.05或P＜0.01）;TP与年龄、病程、心血管疾病呈负相关,与DBP、LDL呈正相关（P＜0.05或P＜0.01）。使用多因素logistic回归对部分可能的混杂因素进行校正后,SDNN、RMSSD、LF、LF/HF、TP降低仍然与CAS发生的风险增加相关（均P＜0.05）。进一步按糖化血红蛋白（≤7.0%、＞7.0%）分层后分析,糖化血红蛋白＞7.0%组的患者SDNN、RMSSD、LF、TP的降低与CAS发生的风险增加相关（P＜0.05）,而在糖化血红蛋白≤7.0%组,仅RMSSD、PNN50有统计学意义（P＜0.05）。结论：2型糖尿病患者HRV参数SDNN、RMSSD、LF、TP降低与CAS发生的风险增加有关,且糖化血红蛋白＞7.0%的患者有更多的HRV参数（SDNN、RMSSD、LF、TP）与CAS相关。     

A model for radiofrequency electromagnetic field predictions at outdoor and indoor locations in the context of epidemiological research

We present a geospatial model to predict the radiofrequency electromagnetic field from fixed site transmitters for use in epidemiological exposure assessment. The proposed model extends an existing model toward the prediction of indoor exposure, that is, at the homes of potential study participants. The model is based on accurate operation parameters of all stationary transmitters of mobile communication base stations, and radio broadcast and television transmitters for an extended urban and suburban region in the Basel area (Switzerland). The model was evaluated by calculating Spearman rank correlations and weighted Cohen's kappa (κ) statistics between the model predictions and measurements obtained at street level, in the homes of volunteers, and in front of the windows of these homes. The correlation coefficients of the numerical predictions with street level measurements were 0.64, with indoor measurements 0.66, and with window measurements 0.67. The kappa coefficients were 0.48 (95%‐confidence interval: 0.35–0.61) for street level measurements, 0.44 (95%‐CI: 0.32–0.57) for indoor measurements, and 0.53 (95%‐CI: 0.42–0.65) for window measurements. Although the modeling of shielding effects by walls and roofs requires considerable simplifications of a complex environment, we found a comparable accuracy of the model for indoor and outdoor points. Bioelectromagnetics 31:226–236, 2010. © 2009 Wiley‐Liss, Inc.     

先天性心脏病患儿介入封堵术治疗前后CRP、NT-proBNP、心率变异性的变化及与术后心功能的关系研究

摘要 目的：探讨先天性心脏病（CHD）患儿介入封堵术治疗前后C-反应蛋白（CRP）、N末端B型利钠肽原（NT-proBNP）、心率变异性（HRV）的变化及与术后心功能的关系。方法：选择2020年10月至2021年6月在本院行介入封堵术治疗的95例CHD患儿为研究对象,采用化学发光法检测血清CRP水平,采用电化学发光免疫技术检测血清NT-proBNP水平,采用24 h动态心电图及12导联同步心电图分析HRV指标,观察手术前后患儿的血清CRP、NT-proBNP水平及HRV指标变化,比较术后不同NYHA心功能分级患儿的血清CRP、NT-proBNP水平和HRV指标,分析患儿术前血清CRP水平、血清NT-proBNP水平、HRV指标与术后NYHA心功能分级的相关性。结果：介入封堵术后患儿血清CRP、NT-proBNP、LF/HF水平逐渐降低,术后3 d、术后1个月时均低于术前,术后1个月时均低于术后3 d时（P<0.025）;而TP、HF、LF、R-R、PNN50%、ASDNN、SDANN、SDNN、rMSSD水平逐渐升高,术后3 d、术后1个月时均高于术前,术后1个月时均高于术后3 d 时（P<0.025）。患儿术后3 d的血清CRP、NT-proBNP水平及LF/HF水平随着NYHA心功能分级的升高而升高,TP、HF、LF、R-R、PNN50%、ASDNN、SDANN、SDNN、rMSSD水平随着NYHA心功能分级的升高而降低（多有P＜0.05）。患儿术后3 d的NYHA心功能分级与治疗前血清CRP、NT-proBNP及LF/HF水平呈负相关,与TP、HF、LF、R-R、PNN50%、ASDNN、SDANN、SDNN、rMSSD水平呈正相关（P＜0.05）。结论：CHD患儿经介入封堵术治疗后,血清CRP、NT-proBNP及HRV指标变化明显,与术后NYHA心功能分级显著相关,血清CRP、NT-proBNP及HRV指标有望成为评估CHD患儿介入封堵术后预后的较敏感性指标。     

急性心肌梗死患者心电图碎裂QRS波与左心室收缩功能、心率变异性及心脏事件的关系研究

目的:探讨急性心肌梗死患者心电图碎裂QRS(f QRS)波与左心室收缩功能、心率变异性及心脏事件的关系。方法:收集2018年1月～2020年1月期间于本院进行治疗的急性心肌梗死患者124例,对患者行心电图检查,根据患者心电图是否出现f QRS波分成f QRS组(59例)和无f QRS组(65例),采用多普勒超声诊断仪对两组患者的左心室收缩功能进行检测对比,并对两组患者进行24h动态心电图检查,对两组患者的心率变异性指标进行统计对比。对两组患者进行为期3个月的随访观察,统计对比两组患者随访期间心脏事件的发生率。结果:f QRS组患者的左室射血分数(LVEF)低于无f QRS组,左心室舒张末期容积(LVEDV)、左心室舒张末期内径(LVEDD)均高于无f QRS组(P0.05)。f QRS组患者总标准差(SDNN)、两个相邻RR间期互差(PNN50)、差值均方根(RMSSD)均低于无f QRS组(P0.05)。随访期间f QRS组患者的心脏事件发生率为35.59%(21/59),高于无f QRS组患者的13.85%(9/65)(P0.05)。结论:伴有心电图f QRS波急性心肌梗死患者的左心室收缩功能降低,心率变异性指标降低,且心脏不良事件发生率增加,心电图f QRS波在一定程度上可作为急性心肌梗死患者心功能、心率变异性及心脏事件发生的监测手段。