The 1.5 GHz Electromagnetic Near-field Used for Cellular Phones Does Not Promote Rat Liver Carcinogenesis in a Medium-term Liver Bioassay

We have recently established that local exposure to a 929.2 MHz electromagnetic near-field, used for cellular phones, does not promote rat liver carcinogenesis in a medium-term bioassay system. In the present study, a 1.439 GHz electromagnetic near-field (EMF), another microwave band employed for cellular phones in Japan, was similarly investigated. Time division multiple access (TDMA) signals for the Personal Digital Cellular (PDC) Japanese cellular telephone standard system were directed to rats through a quarter-wavelength monopole antenna. Numerical dosimetry showed that the peak SARs within the liver were 1.91–0.937 W/kg, while the whole-body average specific absorption rates (SARs) were 0.680–0.453 W/kg, when the time-averaged antenna radiation power was 0.33 W. Exposure was for 90 min a day, 5 days a week, over 6 weeks, to male F344 rats given a single dose of diethylnitrosamine (200 mg/kg, i.p.) 2 weeks previously. At week 3, all rats were subjected to a two-thirds partial hepatectomy. At week 8, the experiment was terminated and the animals were killed. Carcinogenic potential was scored by comparing the numbers and areas of the induced glutathione S-transferase placental form (GST-P)-positive foci in the livers of exposed (48) and sham-exposed rats (48). Despite increased serum levels of corticosterone, adrenocorticotropic hormone (ACTH) and melatonin, the numbers and the areas of GST-P-positive foci were not significantly altered by the exposure. These findings clearly indicated that local body exposure to a 1.439 GHz EMF, as in the case of a 929.2 MHz field, has no promoting effect on rat liver carcinogenesis in the present model.     

应用电磁场治疗膝骨关节炎疗效观察

目的 :探讨电磁场治疗膝骨关节炎的疗效。方法 :将 10 4例患者随机分为治疗组和对照组。治疗组用XT 4 0 0C骨创伤治疗仪治疗 ,对照组口服布洛芬 ,连续 3周。结果 :对于疼痛症状 ,治疗组和对照组治疗效果相当 ,无显著差异 (P >0 .0 5 ) ;对于炎症活动障碍 ,治疗组的治疗效果明显优于对照组 ,差异有显著意义 (P <0 .0 5 )。结论 :电磁场是治疗膝骨关节炎较好的方法     

屏蔽措施对电磁辐射致学习记忆障碍的防护

目的 探讨电磁辐射对大鼠学习记忆的影响及其机制，观察铝箔的不同屏蔽方式对电磁辐射的防护效果。方法 采用主动回避反应(AAR)和一次性被动回避反应(PAR)观察电磁辐射后大鼠学习记忆能力，采用Fura-2荧光检测海马突触体游离钙的变化，以及采用铝箔进行全身屏蔽和躯干屏蔽后对学习记忆能力和海马突触体钙含量的影响。结果 电磁波辐照可引起大鼠长时记忆和短时记忆能力减退，辐照后即刻和24h海马突触体游离钙呈双峰状升高，全身屏蔽后电磁波辐照对大鼠学习记亿能力和海马突触体游离钙基本不产生影响，躯干屏蔽对以上指标白乞变化影响不明显。结论 电磁辐射可明显影响大鼠学习记亿能力和海马突触体游离钙含量，海马突触体游离钙超载可能是大鼠学习记忆障碍的直接原因。全身屏蔽方式对电磁辐射具有较好的防护效果，而躯干屏蔽对电磁辐射基本无防护作用。     

都市环境电磁辐射对青少年神经行为的影响

目的　探讨都市环境各频段电磁波同时混合存在于一个环境内对青少年神经行为的影响。方法　利用WHO推荐的神经毒理学行为试验—神经行为核心测试组合进行检测。结果　高背景环境电磁射组青少年提转捷度、数字译码得分明显高于低背景环境电磁辐射组 (P均 <0 0 5 ) ,而其 (16～ 18岁 )目标追踪试验的总点数和正确点数均明显低于低背景环境电磁辐射组 (P均 <0 0 5 )。结论　大都市现有环境电磁辐射对青少年的手工操作敏感度及眼手协调能力、视觉感知、记忆、模拟学习能力无不良影响 ,但对青少年 (特别是 16～ 18岁的女性 )心理运动稳定性、手部运动速度可能有一定的影响     

复合电磁场水处理装置灭菌效果评价

目的研究复合电磁场水处理装置（简称装置）的灭菌效果并探讨其灭菌机制.方法灭菌试验：用大肠埃希菌8099株制备的模拟水经装置处理60s,并在处理至0,15,30,45和60s时分别采样,于37和44.5℃培养检测菌密度.持续灭菌试验：制备3种水为高压灭菌自来水、经装置消毒灭菌状态处理3min的脱氯自来水、经装置消毒灭菌状态处理3min,再经胶体脱稳状态处理20min的脱氯自来水;以上3种水样均添加大肠埃希菌8099株后静置3h,并于0,0.5,1,2和3h取样,37和44.5℃培养检测菌密度.结果装置在30s内对含菌模拟水样的细菌灭活率达100%;经装置处理后再染菌的水样,60min细菌灭活率仍可达100%.结论复合电磁场水处理装置具有快速高效的直接灭菌功能及一定的持续灭菌功能.     

High‐permittivity solid ceramic resonators for high‐field human MRI

The properties of a ceramic‐based annular dielectric resonator designed for 7 T MRI have been examined. Electromagnetic simulations and experimentally determined modal frequencies agree to within ~1%. The dependence of the resonance frequency of the degenerate quadrature HEM₁₁ modes on hole diameter and shield diameter was also investigated. The constructed coil, with a 2.5 cm diameter hole, had an unloaded Q value of 400, which was reduced to 150 when loaded with a human finger. Simulated and experimental B₁⁺ maps show a high degree of homogeneity with a sensitivity of ~11.5 μT/√W at the centre. A comparison with a loop gap resonator showed an approximately 25% higher sensitivity for the dielectric resonator. High‐resolution images of the digital interphalangeal (DIP) and proximal interphalangeal (PIP) joints of volunteers were acquired in imaging times of less than 2 min. Finally, novel methods of double tuning such ceramic resonators to two relatively close frequencies, e.g. proton and fluorine, have been shown. Copyright © 2013 John Wiley & Sons, Ltd.     

Ultrasound Bone Fracture Sensing and Data Communication: Experimental Results in a Pig Limb Sample

Approximately 6.3 million fractures occur each year in the United States alone. Accurately monitoring the progression of fracture healing is essential to be able to advise patients when it is safe to return to normal activity. The most common method used to confirm and monitor fracture healing is the acquisition of multiple radiographic images over the many months required for healing. This imaging method uses large expensive equipment and exposes patients to high levels of ionizing radiation. In the study described here, we tested another technology for monitoring fracture healing that could minimize the need for multiple radiographic images. We tested a piezoelectric transducer fixed to the surface of a bone that uses electromechanical impedance spectroscopy to measure simulated fractures and transmits the measurement data to an acoustic receiver located externally on the skin surface.     

Assessment of the Fundamental Flexural Guided Wave in Cortical Bone by an Ultrasonic Axial-Transmission Array Transducer

The fundamental flexural guided wave (FFGW), as modeled, for example, by the A0 Lamb mode, is a clinically useful indicator of cortical bone thickness. In the work described in this article, we tested so-called multiridge-based analysis, based on the crazy climber algorithm and short-time Fourier transform, for assessment of the FFGW component recorded by a clinical array transducer featuring a limited number of elements. Methods included numerical finite-element simulations and experiments in bone phantoms and human radius specimens (n = 41). The proposed approach enabled extraction of the FFGW component and determination of its group velocity. This group velocity was in good agreement with theoretical predictions and possessed reasonable sensitivity to cortical width (r² = 0.51, p < 0.001) in the in vitro experiments. It is expected that the proposed approach enables related clinical application. Further work is still needed to analyze in more detail the challenges related to the impact of the overlying soft tissue.     

Boosting jet power in black hole spacetimes

The extraction of rotational energy from a spinning black hole via the Blandford–Znajek mechanism has long been understood as an important component in models to explain energetic jets from compact astrophysical sources. Here we show more generally that the kinetic energy of the black hole, both rotational and translational, can be tapped, thereby producing even more luminous jets powered by the interaction of the black hole with its surrounding plasma. We study the resulting Poynting jet that arises from single boosted black holes and binary black hole systems. In the latter case, we find that increasing the orbital angular momenta of the system and/or the spins of the individual black holes results in an enhanced Poynting flux.