Radio Waves

无线电波
  • 文章类型: Journal Article
    射频(RF)源的广泛使用,从家用电器到电信设备和军事装备,引起人们和监管机构对RF暴露的潜在健康风险的担忧。因此,已经进行了一些体外和体内研究,以研究其生物学效应,特别是非热的,这种非电离辐射。迄今为止,由于已经报道了有争议的结果,这个问题仍在辩论中。此外,不同的射频信号调制对生物系统的影响仍然缺乏研究。本体外研究旨在评估人真皮成纤维细胞(HDF)中连续或脉冲1.6GHzRF的细胞毒性和遗传毒性。
    HDF培养物暴露于连续和脉冲的1.6GHz射频,2小时,与0.4W/kg的比吸收率(SAR)。1.6GHz射频对HDF的潜在生物学效应采用多方法学方法进行了评估,分析对细胞周期的影响,超微结构,蛋白质表达,有丝分裂纺锤体,CREST染色的微核,染色体分离和γ-H2AX/53BP1灶。
    1.6GHzRF暴露修饰了HDF的蛋白质表达和形态。具体来说,不同热休克蛋白(HSP)的表达(即HSP-90,HSP-60和HSP-25)和磷酸-AKT受到影响。此外,连续和脉冲RF都改变了HDF中的细胞骨架组织并增加了溶酶体的数量,而自噬体的形成仅在脉冲RF暴露后观察到。暴露后还发现有丝分裂纺锤体异常。然而,对细胞周期没有显著影响,染色体分离,CREST染色的微核和γ-H2AX/53BP1灶。
    本研究的结果表明,在1.6GHz射频暴露的HDF中没有基因毒性损伤,尽管观察到有丝分裂纺锤体改变,它们没有不良作用。另一方面,暴露的HDF中某些蛋白质表达和细胞超微结构的变化表明,RF可能在形态和分子水平上诱导细胞改变。
    UNASSIGNED: The widespread use of radiofrequency (RF) sources, ranging from household appliances to telecommunications devices and military equipment, raises concerns among people and regulatory agencies about the potential health risks of RF exposure. Consequently, several in vitro and in vivo studies have been done to investigate the biological effects, in particular non-thermal, of this non-ionizing radiation. To date, this issue is still being debated due to the controversial results that have been reported. Furthermore, the impact of different RF signal modulations on biological systems remains poorly investigated. The present in vitro study aims to evaluate the cytotoxicity and genotoxicity of continuous or pulsed 1.6 GHz RF in human dermal fibroblasts (HDF).
    UNASSIGNED: HDF cultures were exposed to continuous and pulsed 1.6 GHz RF, for 2 h, with Specific Absorption Rate (SAR) of 0.4 W/kg. The potential biological effects of 1.6 GHz RF on HDF were assessed with a multi-methodological approach, analyzing the effects on cell cycle, ultrastructure, protein expression, mitotic spindle, CREST stained micronuclei, chromosome segregation and γ-H2AX/53BP1 foci.
    UNASSIGNED: 1.6 GHz RF exposure modified proteins expression and morphology of HDF. Specifically, the expression of different heat-shock proteins (HSP) (i.e., HSP-90, HSP-60, and HSP-25) and phospho-AKT were affected. In addition, both continuous and pulsed RF modified the cytoskeletal organization in HDF and increased the number of lysosomes, while the formation of autophagosomes was observed only after pulsed RF exposure. Mitotic spindle anomalies were also found after exposure. However, no significant effect was observed on cell cycle, chromosome segregation, CREST-stained micronuclei and γ-H2AX/53BP1 foci.
    UNASSIGNED: The results of the present study show the absence of genotoxic damage in 1.6 GHz RF exposed HDF and, although mitotic spindle alterations were observed, they did not have an aneugenic effect. On the other hand, changes in some proteins expression and cell ultrastructure in exposed HDF suggest that RF can potentially induce cell alterations at the morphological and molecular levels.
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  • 文章类型: Journal Article
    目的是评估添加迷迭香标准干提取物(RO)和美学射频对氧化应激标志物过氧化氢酶(CAT)的影响,超氧化物歧化酶(SOD),非蛋白质硫醇(NP-SH),和硫代巴比妥酸反应物质(TBARS)和生化标记甘油三酯,总胆固醇,高密度脂蛋白(HDL)胆固醇,谷氨酸-草酰乙酸转氨酶(TGO/AST),丙酮酸-谷氨酸转氨酶(TGP/ALT),γ-谷氨酰转肽酶(γ-GT),和肌酐。这项研究包括32名接受美容治疗以减少局部脂肪的女性。分为接受安慰剂胶囊的对照组(n=8)和干预组(n=24),再分为A组,B,C,每个有八个成员接受补充100、500和1000毫克/天的标准RO干提取物,分别。通用试验编号(UTN)-U1111-1274-6255。补充RO(500mg/天)表明氧化应激降低(通过NP-SH的显著增加和SOD和CAT酶的减少定量)。射频美容治疗并没有促进氧化应激的增加;然而,它引起了总胆固醇的显著变化,HDL胆固醇,和肌酐。RO是一种具有抗氧化作用的植物,在选定的女性受试者中,其口服食用在肝脏和肾脏标志物方面是安全的。
    The objective were to evaluate the effects of supplementation of standardized dry extract of Rosmarinus officinalis (RO) and the application of aesthetic radiofrequency on the oxidative stress markers catalase (CAT), superoxide dismutase (SOD), non-protein thiols (NP-SH), and thiobarbituric acid reactive species (TBARS) and the biochemical markers triglycerides, total cholesterol, high density lipoprotein (HDL) cholesterol, glutamic-oxaloacetic transaminase (TGO/AST), pyruvic-glutamic transaminase (TGP/ALT), gamma glutamyl transpeptidase (gamma-GT), and creatinine. This study included 32 women received the aesthetic therapy to reduce localized fat. They were divided into the control group (n = 8) receiving placebo capsules and the intervention group (n = 24) subdivided into Group A, B, and C, each with eight members receiving supplementation with 100, 500, and 1000 mg/day of standardized dry extract of RO, respectively. The Universal Trial Number (UTN) - U1111-1274-6255. Supplementation with RO (500 mg/day) demonstrated a reduction in oxidative stress (quantified with through a significant increase in NP-SH and a reduction in SOD and CAT enzymes). The radiofrequency aesthetic treatment did not promote an increase in oxidative stress; however, it caused significant changes in total cholesterol, HDL cholesterol, and creatinine. RO is a plant with antioxidant effects and its oral consumption is safe in selected women subjects in hepatic and renal markers.
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  • 文章类型: Journal Article
    近年来,技术的快速发展引起了人们的关注。我们研究了手机产前暴露于900MHz射频(RF)的影响以及芳樟醇对学习和记忆的保护作用,青春期雄性和雌性后代大鼠的焦虑。妊娠大鼠分为四组:对照组,波浪,波浪+芳樟醇,和芳樟醇。大鼠通过管饲法接受芳樟醇(25mg/kg)21天。从怀孕的第0天至第21天进行照射。后代在出生后第50天和第60天进行了行为和电生理测试。怀孕期间暴露于RF会在EPM测试中引起焦虑样行为,并在Morris水迷宫和穿梭箱测试中损害学习和记忆。背侧海马CA3-CA1突触的电生理特性和突触可塑性显示fEPSP幅度和斜率降低。与各自的对照相比,所有组的雄性和雌性后代的微量元素水平都是一致的。在海马组织中,铁的含量,Cu,Mn,以及Cu/Zn比,与对照组相比,暴露组(波组)的显着更高。此外,暴露组海马组织中的Zn水平显着降低。芳樟醇给药减轻了铁的过度增加,Cu,Mn,和Cu/Zn比,并标准化了微量元素的破坏水平,除了雄性和雌性后代的锌含量。在EPM和穿梭箱测试中观察到性别差异,女性比男性更敏感。总之,我们的研究表明,产前暴露于手机辐射会导致类似压力的行为,扰乱学习和记忆,改变子代海马电生理特性和微量元素平衡。用芳樟醇治疗可减轻这些有害影响,强调其作为治疗干预的潜力。这些发现有助于我们了解产前环境暴露对神经发育的影响,并提供对神经保护的潜在策略的见解。
    Recent years, the rapid advancement of technology has raised concerns. We studied the effects of prenatal exposure to 900 MHz radiofrequency (RF) from mobile phones and the protective effects of linalool on learning and memory, and anxiety in adolescent male and female offspring rats. Pregnant rats were divided into four groups: control, wave, wave + linalool, and linalool. Rats received linalool (25mg/kg) by gavage for 21 days. Irradiation was conducted from day 0 to day 21 of pregnancy. Offsprings underwent behavioral and electrophysiological tests on days 50 and 60 after birth. Exposure to RF during pregnancy caused anxiety-like behavior in the EPM test and impairment of learning and memory in the Morris water maze and shuttle box tests. Electrophysiological properties and synaptic plasticity of the dorsal hippocampal CA3-CA1 synapse showed a decrease in fEPSP amplitude and slope. The trace element levels in both male and female offspring were consistent across all groups compared to their respective controls. In the hippocampus tissue, the levels of Fe, Cu, and Mn, as well as the Cu/Zn ratio, were significantly higher in the exposed groups (wave groups) compared to their controls. Moreover, Zn levels were significantly lower in the hippocampus tissue of the exposed groups. Linalool administration mitigated the excessive increase in Fe, Cu, Mn, and Cu/Zn ratio and normalized the disrupted levels of trace elements, except for Zn levels in both male and female offspring. Sex differences were observed in the EPM and shuttle box tests, females were more sensitive than males. In summary, our study demonstrates that prenatal exposure to mobile phone radiation induces stress-like behaviors, disrupts learning and memory, alters hippocampal electrophysiological properties and trace element balance in offspring. Treatment with linalool mitigates these deleterious effects, highlighting its potential as a therapeutic intervention. These findings contribute to our understanding of the impact of prenatal environmental exposures on neurodevelopment and offer insights into potential strategies for neuroprotection.
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  • 文章类型: Journal Article
    目的:研究在猪皮肤上使用固定尖端的微等离子体射频(MPRF)的组织学特性。
    方法:两只巴马小型猪在八组参数(功率,持续时间,并通过)在背侧皮肤上。立即从每个治疗区收集皮肤样本,在治疗后1周和1、3和6个月。进行苏木精和伊红(HE)和Masson染色以评估组织学变化以及新生。免疫组化法检测热休克蛋白47(HSP47)和热休克蛋白72(HSP72)的动态变化。
    结果:皮肤损伤随着脉冲能量的增加而增加,持续时间,和通过。长时间或重复治疗可能会导致特别严重的皮肤损伤。在伤口愈合过程中,新生的真皮胶原蛋白被重新排列。HSP47和HSP72的分布与胶原重塑的程度一致。治疗后1个月达到峰值。
    结论:MPRF可有效引起表皮消融,真皮胶原蛋白增生,和重塑。增加治疗强度时,增加功率应该是首选。对于更长的持续时间或重复治疗,应注意避免过度的皮肤创伤。
    OBJECTIVE: To investigate the histological properties of microplasma radiofrequency (MPRF) using a stationary tip in different treatment strategies on porcine skin.
    METHODS: Two Bama miniature pigs received MPRF treatment with two types of stationary tips in eight groups of parameters (power, duration, and pass) on dorsal skin. Skin samples were collected from each treatment zone immediately, at 1 week and 1, 3, and 6 months after treatment. Hematoxylin and eosin (HE) and Masson staining were performed to assess histologic changes as well as neocollagenesis. The dynamic changes of heat shock protein 47 (HSP47) and heat shock protein 72 (HSP72) were also detected by immunohistochemistry.
    RESULTS: Skin damage increased with pulse energy, duration, and pass. Longer durations or repeated treatments may cause particularly severe skin damage. During the wound healing process, the newborn collagen of the dermis is rearranged. The distribution of HSP47 and HSP72 was consistent with the extent of collagen remodeling. It peaked 1 month after treatment.
    CONCLUSIONS: MPRF can effectively cause epidermal ablation, dermal collagen hyperplasia, and remodeling. Increasing power should be the first choice when increasing treatment intensity. For longer durations or repeated treatments, caution should be taken to avoid excessive skin trauma.
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  • 文章类型: Journal Article
    头痛是一种常见疾病,在全世界范围内都有很大的疾病负担。由于射频电磁场(RF-EMFs),长期使用手机对头痛的潜在影响引起了人们的关注。我们通过分析由荷兰和英国队列组成的手机使用与健康队列研究(COSMOS)(N=78,437)的汇总数据,前瞻性地探索了基线(2009-2012)使用手机和随访(2015-2018)头痛之间的关联。头痛的频率,偏头痛,和手机使用信息,包括免提设备的使用和发短信的频率,是自我报告的。我们收集了客观的操作员数据,以获得语音通话持续时间的回归校准估计。在呼叫时间和短信相互调整的模型中,呼叫时间高类别的参与者显示调整后的优势比(OR)为1.04(95%CI:0.94-1.15),随着通话时间的增加,没有明显的头痛报告趋势。然而,我们发现,在高类别的短信中,每周头痛的风险增加(OR=1.40,95%CI:1.25-1.56),随着发短信的增加,报告头痛的人数明显增加。由于短信对RF-EMFs的暴露可以忽略不计,我们的研究结果表明,RF-EMFs以外的机制是我们在手机用户中发现的头痛风险增加的原因.
    Headache is a common condition with a substantial burden of disease worldwide. Concerns have been raised over the potential impact of long-term mobile phone use on headache due to radiofrequency electromagnetic fields (RF-EMFs). We explored prospectively the association between mobile phone use at baseline (2009-2012) and headache at follow-up (2015-2018) by analysing pooled data consisting of the Dutch and UK cohorts of the Cohort Study of Mobile Phone Use and Health (COSMOS) (N = 78,437). Frequency of headache, migraine, and information on mobile phone use, including use of hands-free devices and frequency of texting, were self-reported. We collected objective operator data to obtain regression calibrated estimates of voice call duration. In the model mutually adjusted for call-time and text messaging, participants in the high category of call-time showed an adjusted odds ratio (OR) of 1.04 (95 % CI: 0.94-1.15), with no clear trend of reporting headache with increasing call-time. However, we found an increased risk of weekly headache (OR = 1.40, 95 % CI: 1.25-1.56) in the high category of text messaging, with a clear increase in reporting headache with increasing texting. Due to the negligible exposure to RF-EMFs from texting, our results suggest that mechanisms other than RF-EMFs are responsible for the increased risk of headache that we found among mobile phone users.
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  • 文章类型: Journal Article
    背景:在超高场下通过磁共振成像对具有植入的导电装置的患者进行成像受到与由于来自入射电磁场的能量耦合到植入物中而引起与植入物相邻的组织加热的可能性相关的不确定性的阻碍。同行评审文献中的现有数据,包括组织加热及其替代的场强比较,比吸收率(SAR),是稀缺和矛盾的,导致对使用此类设备的患者成像安全性的进一步怀疑。
    目的:通过全波电磁模拟研究了与不同长度和频率为64至498MHz的骨科螺钉相邻的射频诱导SAR,以提供跨MRI场强的SAR的准确比较。
    方法:使用偶极天线进行RF传输,以实现与位于天线中点上方120mm的螺钉相切的均匀电场,嵌入模拟骨骼的材料中.在没有螺钉存在的情况下,天线的输入功率被限制为实现以下目标:(i)E=100V/m,(ii)B1+=2μT,和(iii)全球平均SAR=3.2W/kg。在螺钉周围的体积中以0.2mm的空间分辨率进行模拟,导致76-137MCells,注意每种情况下最大1g平均SAR值。在128和297MHz下对嵌入肌肉组织中的螺钉重复模拟。
    结果:峰值SAR,发生在共振螺杆长度,当偶极天线的输入功率被限制以在螺钉位置处的背景组织中实现恒定的电场时,随着频率的降低而大幅增加。当限制输入功率以实现恒定的B1+和全局平均SAR时,观察到类似的模式。在297和128MHz之间的SAR比较中,嵌入螺钉的组织的介电特性占主导地位。
    结论:研究设计允许在频率和植入物长度之间进行SAR的直接比较,而不会受到可变入射电场的混淆作用。对于接近共振长度的植入物,较低的频率会产生明显较大的SAR值,而最坏情况下沿螺钉长度的均匀入射电场。数据可以为在新的临床场强7特斯拉下对具有骨科植入物的患者进行成像的风险-效益评估提供信息。
    BACKGROUND: The imaging of patients with implanted electrically-conductive devices via magnetic resonance imaging at ultra-high fields is hampered by uncertainties relating to the potential for inducing tissue heating adjacent to the implant due to coupling of energy from the incident electromagnetic field into the implant. Existing data in the peer-reviewed literature of comparisons across field strengths of tissue heating and its surrogate, the specific absorption rate (SAR), is scarce and contradictory, leading to further doubts pertaining to the safety of imaging patients with such devices.
    OBJECTIVE: The radiofrequency-induced SAR adjacent to orthopedic screws of varying length and at frequencies of 64 to 498 MHz was investigated via full-wave electromagnetic simulations, to provide an accurate comparison of SAR across MRI field strengths.
    METHODS: Dipole antennas were used for RF transmission to achieve a uniform electric field tangential to the screws located 120 mm above the antenna midpoints, embedded in a bone-mimicking material. The input power to the antennas was constrained to achieve the following targets without the screw present: (i) E = 100 V/m, (ii) B1 +  = 2 μT, and (iii) global-average-SAR = 3.2 W/kg. Simulations were performed with a spatial resolution of 0.2 mm in the volume surrounding the screws, resulting in 76-137 MCells, noting the maximum 1 g-averaged SAR value in each case. Simulations were repeated at 128 and 297 MHz for screws embedded in muscle tissue.
    RESULTS: The peak SAR, occurring at the resonant screw length, substantially increased as the frequency decreased when the input power to the dipole antenna was constrained to achieve constant electric field in background tissue at the screws\' locations. A similar pattern was observed when constraining input power to achieve constant B1 + and global-average-SAR. The dielectric properties of the tissue in which the screws were embedded dominated the SAR comparisons between 297 and 128 MHz.
    CONCLUSIONS: The study design allowed for a direct comparison to be performed of SAR across frequencies and implant lengths without the confounding effect of variable incident electric field. Lower frequencies produced substantially larger SAR values for implants approaching the resonant length for the worst-case uniform incident electric field along the screws\' length. The data may inform risk-benefit assessments for imaging patients with orthopedic implants at the new clinical field strength of 7 Tesla.
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  • 文章类型: Journal Article
    目的:对RF场可穿透的椭圆形PET插入物进行MRI兼容性研究,该插入物将MRI内置人体RF线圈作为发射器和接收器。
    方法:使用十二个电浮动RF屏蔽PET探测器模块来构建主轴为440mm的原型椭圆形PET插入物,350毫米的短轴,和225毫米的轴向长度。PET检测器模块的电浮动通过使用塑料带将电缆屏蔽与检测器屏蔽隔离来实现。对发射(B1)射频场进行了研究,图像信噪比(SNR),以及3T临床MRI系统中均匀圆柱形(直径:160mm,长度:260mm)体模(NaClNiSO4溶液)的RF脉冲幅度(Verio,西门子,Erlangen,德国)。
    结果:椭圆形插入物的B1图与仅MRI场反应相似。与仅MRI值相比,信噪比降低51%,45%,59%的人被看到,分别,对于自旋回波(SE),梯度回波(GE),和回声平面(EPI)图像的情况下的椭圆形PET插入。此外,SE所需的RF脉冲幅度,GE,和EPI序列是,分别,1.93、1.85和1.36倍。然而,椭圆形插入物的平均射频接收灵敏度降低了30%。
    结论:原型浮动PET插入物是临床MRI系统的安全问题,并且该兼容性研究为开发用于现有MRI系统的大型身体尺寸浮动PET插入件提供了间隙。由于插入件的射频屏蔽,与仅使用MRI的病例相比,需要相对较大的射频功率.由于这一点,也由于身体线圈的低射频灵敏度,SNR大大降低。
    OBJECTIVE: To perform an MRI compatibility study of an RF field-penetrable oval-shaped PET insert that implements an MRI built-in body RF coil both as a transmitter and a receiver.
    METHODS: Twelve electrically floating RF shielded PET detector modules were used to construct the prototype oval PET insert with a major axis of 440 mm, a minor axis of 350 mm, and an axial length of 225 mm. The electric floating of the PET detector modules was accomplished by isolating the cable shield from the detector shield using plastic tape. Studies were conducted on the transmit (B1) RF field, the image signal-to-noise ratio (SNR), and the RF pulse amplitude for a homogeneous cylindrical (diameter: 160 mm and length: 260 mm) phantom (NaCl + NiSO4 solution) in a 3 T clinical MRI system (Verio, Siemens, Erlangen, Germany).
    RESULTS: The B1 maps for the oval insert were similar to the MRI-only field responses. Compared to the MRI-only values, SNR reductions of 51%, 45%, and 59% were seen, respectively, for the spin echo (SE), gradient echo (GE), and echo planar (EPI) images for the case of oval PET insert. Moreover, the required RF pulse amplitudes for the SE, GE, and EPI sequences were, respectively, 1.93, 1.85, and 1.36 times larger. However, a 30% reduction in the average RF reception sensitivity was observed for the oval insert.
    CONCLUSIONS: The prototype floating PET insert was a safety concern for the clinical MRI system, and this compatibility study provided clearance for developing a large body size floating PET insert for the existing MRI system. Because of the RF shield of the insert, relatively large RF powers compared to the MRI-only case were required. Because of this and also due to low RF sensitivity of the body coil, the SNRs reduced largely.
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  • 文章类型: Journal Article
    目的:研究B0≤3T$${B}_0\\le3\\mathrm{T}$$的体线圈的并行传输(pTx)RF控制模式的安全性和性能方面。
    方法:对于B0=0.5T$${B}_0=0.5\\mathrm{T}$$,在心脏成像位置进行了11种人体体素模型的电磁模拟,1.5T$$1.5\\mathrm{T}$$和3T$$$3\\mathrm{T}$$以及具有可配置数量的发射通道(1、2、4、8、16)的体线圈。考虑了三种安全模式:“SAR控制模式”(SCM),在比吸收率(SAR)直接受到限制的情况下,a\'相位不可知SAR控制模式\'(PASCM),忽略相位信息,和功率控制模式(PCM),其中每个通道的电压幅度是有限的。对于任一模式,根据一组“锚”模拟建立安全限值,然后在“目标”模拟中对以前未见过的模型进行评估。比较可以得出考虑患者解剖结构变化的安全因素。在各自的安全要求下,根据B1+$${B}_1^{+}$$振幅和均匀性比较了所有控制模式。
    结果:如果只研究一个或两个锚模型,但它们会随着锚数量的增加而缩小,则需要大的安全系数(大约五个)。对于SCM,可实现的B1+$${B}_1^{+}$$是最高的,但是当包括安全系数时,这种优势会降低。PCM似乎对受试者的变化更有鲁棒性。PASCM性能主要介于SCM和PCM之间。与标准圆极化(CP)激励相比,如果始终强制执行本地SAR限制,pTx会提供较小的B1+$${B}_1^{+}$$$改进。
    结论:PTx体线圈可以安全地在B0≤3T$${B}_0\\le3\\mathrm{T}$$下使用。必须考虑患者解剖结构的不确定性,然而,通过模拟许多模型。
    OBJECTIVE: To investigate safety and performance aspects of parallel-transmit (pTx) RF control-modes for a body coil at B 0 ≤ 3 T $$ {B}_0\\le 3\\mathrm{T} $$ .
    METHODS: Electromagnetic simulations of 11 human voxel models in cardiac imaging position were conducted for B 0 = 0.5 T $$ {B}_0=0.5\\mathrm{T} $$ , 1.5 T $$ 1.5\\mathrm{T} $$ and 3 T $$ 3\\mathrm{T} $$ and a body coil with a configurable number of transmit channels (1, 2, 4, 8, 16). Three safety modes were considered: the \'SAR-controlled mode\' (SCM), where specific absorption rate (SAR) is limited directly, a \'phase agnostic SAR-controlled mode\' (PASCM), where phase information is neglected, and a \'power-controlled mode\' (PCM), where the voltage amplitude for each channel is limited. For either mode, safety limits were established based on a set of \'anchor\' simulations and then evaluated in \'target\' simulations on previously unseen models. The comparison allowed to derive safety factors accounting for varying patient anatomies. All control modes were compared in terms of the B 1 + $$ {B}_1^{+} $$ amplitude and homogeneity they permit under their respective safety requirements.
    RESULTS: Large safety factors (approximately five) are needed if only one or two anchor models are investigated but they shrink with increasing number of anchors. The achievable B 1 + $$ {B}_1^{+} $$ is highest for SCM but this advantage is reduced when the safety factor is included. PCM appears to be more robust against variations of subjects. PASCM performance is mostly in between SCM and PCM. Compared to standard circularly polarized (CP) excitation, pTx offers minor B 1 + $$ {B}_1^{+} $$ improvements if local SAR limits are always enforced.
    CONCLUSIONS: PTx body coils can safely be used at B 0 ≤ 3 T $$ {B}_0\\le 3\\mathrm{T} $$ . Uncertainties in patient anatomy must be accounted for, however, by simulating many models.
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  • 文章类型: Observational Study
    背景:睡眠干扰是暴露于移动通信中使用的射频电磁场(RF-EMF)的人们最常见的健康投诉之一,特别是那些认为自己是EMF过敏(EHS)的人。我们旨在调查EHS状况本身是否与睡眠投诉有关。因为编码L型基因的等位基因变异体,电压门控钙通道Cav1.2(CACNA1C)以前与睡眠投诉有关,让人想起EHS个体报告的睡眠投诉,我们还探讨了自我评估的EHS状态和睡眠质量是否与这些基因变异相关.
    方法:共有2\'040名18-30岁的参与者(1\'381名女性)在线完成,关于EMF敏感性的验证问卷,主观睡眠质量,白天嗜睡,睡眠期间的心理状态,和昼夜偏好。他们还提供了用于对CACNA1C的三种功能变体(rs7304986、rs16929277和rs2302729)进行基因分型的唾液样品。认可问题“您是电过敏吗?”的合格参与者被认为是“EHS”(n=105),那些否认这个问题,但认为由于普遍存在的电磁污染而产生有害健康症状的人作为“归因者”(n=254),其余参与者为“非EHS”(n=1'406)。我们将EHS和归因者组合成一个组进行二元分析。在探索性分析中,然后我们测试了EMF灵敏度之间可能的关联,使用线性和逻辑回归的主观睡眠变量和CACNA1C变体。我们用年龄,性别,教育水平,睡眠障碍的存在和习惯性使用手机作为协变量,并通过Benjamini-Hochberg错误发现率进行多重比较校正。
    结果:EHS/归因者一致报告睡眠潜伏期延长,睡眠质量下降,与非EHS相比,睡意更高,夜间睡眠更多。习惯性使用手机与自我评估的睡眠延迟和睡眠质量评分无关。虽然CACNA1C变异体rs2302729的T等位基因与两者相关,自我报告的EMF敏感性和降低的主观睡眠质量,我们没有发现EHS通过这种等位基因变异介导睡眠质量受损这一假设的证据.
    结论:不考虑报告的RF-EMF暴露,自评EHS/归因者对主观睡眠质量的评价低于非EHS个体。
    背景:瑞士国家临床试验门户(SNCTP000002285)和ClinicalTrials.gov(NCT03074617)。
    Disturbed sleep is among the most frequent health complaints of people exposed to radio frequency electromagnetic fields (RF-EMF) used in mobile telecommunication, particularly in individuals who consider themselves as EMF hypersensitive (EHS). We aimed at investigating whether the EHS status per se is associated with sleep complaints. Because allelic variants of the gene encoding the L-type, voltage-gated calcium channel Cav1.2 (CACNA1C) were previously associated with sleep complaints reminiscent of those reported by EHS individuals, we also explored whether self-rated EHS status and sleep quality associate with these gene variants.
    A total of 2\'040 participants (1\'381 females) aged 18-30 years completed online, validated questionnaires on EMF sensitivity, subjective sleep quality, daytime sleepiness, mentation during sleep, and diurnal preference. They also provided a saliva sample for genotyping three functional variants of CACNA1C (rs7304986, rs16929277 and rs2302729). Eligible participants endorsing the question \"Are you electro-hypersensitive?\" were considered as \"EHS\" (n = 105), those denying this question yet believing to develop detrimental health symptoms due to prevailing electromagnetic pollution as \"attributers\" (n = 254), and the remaining participants as \"non-EHS\" (n = 1\'406). We combined the EHS and attributers into one group for binary analyses. In exploratory analyses, we then tested possible associations between EMF sensitivity, subjective sleep variables and CACNA1C variants using linear and logistic regression. We used age, sex, level of education, presence of sleep disorders and habitual mobile phone use as covariates and corrected with Benjamini-Hochberg False Discovery Rate for multiple comparisons.
    The EHS/attributers consistently reported prolonged sleep latency, reduced sleep quality, higher sleepiness and more nocturnal mentation when compared to non-EHS. Habitual mobile phone use was not associated with self-rated sleep latency and sleep quality scores. While the T-allele of variant rs2302729 of CACNA1C was associated with both, self-reported EMF sensitivity and reduced subjective sleep quality, we found no evidence for the hypothesis that EHS mediates impaired sleep quality via this allelic variant.
    Irrespective of reported RF-EMF exposure, self-rated EHS/attributers rated subjective sleep quality worse than non-EHS individuals.
    Swiss National Clinical Trials Portal (SNCTP000002285) and ClinicalTrials.gov (NCT03074617).
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  • 文章类型: Journal Article
    这项研究的目的是评估与MRI身体RF线圈结合使用的部分环RF屏蔽椭圆形正电子发射断层扫描(PET)插入物的RF场响应。部分环PET插入物特别适用于介入调查(例如,三模态PET/MRI/超声成像)和术中(例如,机器人手术)PET/MRI研究。在这项研究中,我们使用电浮动法拉第射频屏蔽笼来构建椭圆形和圆柱形PET插件的不同部分环配置,并在射频场进行实验,3T临床MRI系统中均匀体模的自旋回波和梯度回波图像。对于每个几何图形,通过从PET环的不同位置移除相对的一对或单个屏蔽笼来研究部分环配置。与只做核磁共振的病例相比,平均射频均匀性降低,翻转角,第一和第三象限的探测器开口的信噪比约为13%,15%,43%,分别,而该值为8%,23%,48%,分别,用于第二和第四象限中的探测器开口。对于不同的部分环配置,RF场分布也变化。可以得出结论,对于两个插入件的第一和第三象限中的检测器开口,场穿透率很高。
    The purpose of this study is to evaluate the RF field responses of partial-ring RF-shielded oval-shaped positron emission tomography (PET) inserts that are used in combination with an MRI body RF coil. Partial-ring PET insert is particularly suitable for interventional investigation (e.g., trimodal PET/MRI/ultrasound imaging) and intraoperative (e.g., robotic surgery) PET/MRI studies. In this study, we used electrically floating Faraday RF shield cages to construct different partial-ring configurations of oval and cylindrical PET inserts and performed experiments on the RF field, spin echo and gradient echo images for a homogeneous phantom in a 3 T clinical MRI system. For each geometry, partial-ring configurations were studied by removing an opposing pair or a single shield cage from different positions of the PET ring. Compared to the MRI-only case, reduction in mean RF homogeneity, flip angle, and SNR for the detector opening in the first and third quadrants was approximately 13%, 15%, and 43%, respectively, whereas the values were 8%, 23%, and 48%, respectively, for the detector openings in the second and fourth quadrants. The RF field distribution also varied for different partial-ring configurations. It can be concluded that the field penetration was high for the detector openings in the first and third quadrants of both the inserts.
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