量度微波生物效应的实验剂量学研究进展

微波剂量学是对沉积在生物体内的微波能量及其分布的物理量度。它通常用比吸收率（SAR）来表示生物效应和作为防护限值量，SAR不仅与入射微波有关，还与生物体的电特性、尺寸、形状、结构有关。本文综述了几种确定SAR的实验方法，包括能差法、电场法、测温法、量热法和热像法，并对其用途和误差来源进行了分析。     

高功率脉冲微波辐照对大鼠血清激素水平影响的研究

目的：通过对高功率脉冲微波（HPPMW）辐照后Wistar大鼠血清中睾酮（Testo)、雌二醇（E2）、促甲状腺激素（TSH）、游离甲状腺素T4（FT4）、皮质醇（Cort)、醛固酮（Ald)及生长激素（HGH）的动态观察,以探讨HPPMW对内分泌系统的影响。用高功率脉冲微波源,以功率密度为3050W／cm^2脉冲微波（频率为5．4GHz,脉宽为26ns)辐照辐照组动物。于辐照后1h,6h,24h,7d,14d及28d分别采血,用放射免疫法在FT630放免疫定仪上进行统一测定。所有数据经SPSS8．0统计处理。结果：大鼠被辐照后,其血清E2在早期变化不明显,但在14d时明显升高（P＜0．01）;Testo辐照后1h和14d明显下降（P＜0．05）;TSH于辐照后逐渐升高,14d到28d时明显增高（P＜0．05）;FT4辐照后1h明显升高（P＜0．05）;TSH于辐照后逐渐升高,14d到28d时明显增高（P＜0．05）;FT4辐照后1h明显升高（P＜0．05）后逐渐降低,在28d下降到最低点（P＜0．01）;Cort辐照后1h即升高,14d达到峰值（P＜0．05）;Ald于照后6h-14d略低于对照组,28d恢复;HGH辐照后明显低于照前水平,在28d下降到最低点（P＜0．05）。结论LHPPMW可引起大鼠血清激素水平的紊乱。既有早期影响,也表现为一定的持续效应。提示HPPMW可能直接引起大鼠内分泌系统的损伤。     

脉冲微波联合中药经皮导入辅助治疗儿童肺炎疗效观察

目的：观察脉冲微波联合中药在肺俞穴经皮导入辅助治疗儿童肺炎的临床疗效。方法：将肺炎患儿265例随机分为观察组135例和对照组130例,观察组在常规治疗（抗感染、退热、化痰止咳、吸氧等）基础上加用脉冲微波在肺俞穴经皮导入中药,2次/d,每次20min,连续治疗5天为1个疗程;对照组采用常规治疗。结果：观察组发热病例退热时间、肺部啰音消失时间、咳嗽消失时间均显著短于对照组（P〈0.01）。观察组总有效率85.9%,对照组72.3%,两组比较差异显著（P〈0.05）。结论：儿童肺炎在常规治疗基础上辅以脉冲微波联合中药经皮导入疗效优于常规治疗。     

微波辐射生物效应的量效关系研究进展

微波技术广泛应用于家庭、工业、通信、医疗和军事等方面，其对人体的危害也越来越受重视。本文对微波辐射后神经、内分泌、心脏和生殖等方面损伤的量效关系进行了综述。     

脉冲电场的生物效应与相关应用

脉冲电场是一种高场强超短电脉冲,包含有从低频到高频的多种频率,具有上升时间短与作用时间短等不同于一般直流电与静电场的特点。大量研究认为,脉冲电场物理参数(脉宽、场强、频率)的改变对细胞产生不同的生物学效应,如细胞膜的电穿孔、钙离子释放、细胞增殖、基因表达增强等。脉冲电场其在临床中也有所应用。现将脉冲电场对细胞的生物作用机制和临床应用进行综述。     

高功率脉冲微波辐照对大鼠胰腺及血清一氧化氮和内皮素的影响

目的 观察不同剂量高功率脉冲微波辐照对SD大鼠胰腺形态学及血清一氧化氮、内皮素的影响.方法 80只SD大鼠随机分为4组(n=20),其中1组为对照组,其余3组为辐照组,各组再按取材时间分为14、24、48及72 h4个亚组(n=5),辐照组分别接受104、105、4×105脉冲高功率脉冲微波辐照,辐照后14、24、48及72 h观察胰腺光镜、电镜下的形态学改变,分别以生物化学法、放射免疫法测定血清淀粉酶、一氧化氮(NO)及内皮素(ET)含量.结果 辐照组大鼠光镜下可见胰腺毛细血管扩张充血,电镜下104、105脉冲组可见胰腺细胞轻度损伤,表现为线粒体肿胀、粗面内质网扩张及核内染色质边集;4 × 105脉冲组损伤更加明显,各组均以24和48 h损伤最为严重.与对照组相比,在辐照后14和24 h,辐照组血清淀粉酶降低(F=12.58、11.73,P＜0.05),而内皮素含量升高(F =4.50、4.49,P＜0.05),同时在辐照后各时间点NO含量均增高(F=17.51、41.72、19.98、32.64,P＜0.05),随辐照剂量的增加,NO升高越明显.结论 高功率脉冲微波可引起大鼠胰腺毛细血管扩张和胰腺细胞轻度损伤,损伤程度与辐射剂量有一定的关系,辐射剂量越大,损伤越严重,其机制可能与血清内皮素和NO升高有关.     

高功率脉冲微波照射时大鼠体内SAR值计算

目的 计算高功率脉冲微波照射条件下大鼠体内的比吸收率(Specific Absorption Ratr，SAR)分布。方法在建立的脉冲辐射场及大鼠电磁模型的基础上，采用时域有限差分法计算大鼠体内的感生电场分布，进而得到比吸收率。结果计算了不同脉宽和重复频率条件下的峰值比吸收率和平均比吸收率，并按防护标准的要求分别计算了SAR1、SAR10和WBA-SAR。结论 照射条件相同，仪改变微波脉冲宽度，峰值比吸收率变化很小；在同一次照射中，比吸收率按SAR1 Max、SAR10 Max和全身平均SAR值依次下降，存在局部“热点”；在相同的远场照射条件下，实验动物越小，全身平均SAR值越大。     

极低频脉冲电磁场细胞生物效应及机制的研究

目的 研究ELF脉冲电磁波照射细胞前后细胞胞浆Ca2 浓度的变化及产生该变化的机理.方法 以实验为基础,对细胞胞浆Ca2 浓度进行时一频分析,进而研究ELF脉冲电磁波在细胞胞浆Ca2 浓度时一频域内产生的生物学效应.结果 给出细胞胞浆Ca2 受ELF脉冲电磁场照射前(a)后(b)的PHMx(t,v)等值线图,并结合液晶生物膜模型,应用液晶电流体动力不稳定的特性阐述了产生该生物效应的机理.结论细胞胞浆Ca2 浓度在时一频域内有其固有的频谱特征,其中包括连续谱和离散谱.有的参数的电磁波可在细胞胞浆Ca2 浓度的时一频域内产生生物学效应而有的参数的电磁波却不能.若能够产生生物学效应,则有两个特征:一是使胞浆Ca2 浓度在时一频域内的连续谱变窄了;二是使离散谱的分布和离散谱的频率发生了变化.同时,能够在细胞胞浆Ca2 浓度的时一频域内产生生物学效应的电磁波脉冲频率和脉冲强度是离散和间隔的.     

三种常见介入诊疗中机房内的辐射场分布

目的 测试3种常见介入诊疗中机房内的辐射场分布,为介入放射工作人员的防护和安全操作提供基础数据。方法 在介入诊疗床周围的水平面和介入放射工作人员经常停留区域的立面,选择不同的点放置热释光剂量计,根据选定的实验条件分组照射,结束后将热释光剂量计带回实验室测量并计算辐射场剂量。结果 相同位置的数据大部分符合心血管介入诊疗>脑血管介入诊疗>肝脏介入诊疗;同种介入诊疗在相同位置的剂量大都符合高剂量组>中剂量组>低剂量组,该结果与有用线束剂量大小一致,与透视时间的长短成正比。个别不符合以上规律的数据存在测量误差或实验偏差。结论 肝脏和脑血管介入诊疗时,辐射剂量相对较低,3 m以外的辐射剂量基本可以忽略。心血管介入诊疗时,离X射线管中心点越远,剂量降低越多。辐射场中术者、第一助手和第二助手站立处的剂量较高,患者的头端、足端方向剂量较低。     

电磁辐射和微波的生物学效应

电磁辐射广泛存在于人类的生存环境之中。人们在利用电磁辐射和微波为人类的健康服务的同时,也越来越多地认识到其对健康的危害。目前电磁辐射已成为损伤人类健康的最主要物理因素之一。本文综述了近年来电磁辐射和微波的生物学机制、对人体各组织器官的不良影响、研究中存在的问题以及研究方向。     

微波辐射合成藜芦醛条件的探讨

目的探讨微波辐射合成藜芦醛的适宜条件。方法分别以180,260,340,420W的微波及2,3,4,5,6,7,8min的辐射时间观察藜芦醛的收率,并与传统油浴加热法进行比较。结果微波辐射功率260W时收率最佳且比较稳定,该功率下最佳反应时间为5min;与普通油浴法比较微波辐射法具有收率高、耗时短、反应完全等优点。结论微波辐射法制备藜芦醛反应时间短、收率高、反应完全;微波辐射的最佳条件为功率260W,时间5min。     

高功率微波辐射损伤防护药物研究进展

随着科技的进步,微波被广泛运用到各个领域,给人类带来便利的同时,其潜在的健康损害普遍受到各国政府和科研人员的关注。高功率微波（ high power microwave ,HPM）在高新技术武器和新概念武器中的应用,使得部队官兵暴露于HPM环境下的概率增加。已有研究明确证实,特定条件的微波辐射对神经系统、免疫系统、心血管系统以及生殖系统存在不同程度的损伤效应。因此,在做好物理防护的同时,积极有效的医学防护,对于减小HPM损伤效应、提高部队官兵作战能力具有重要的意义。该文针对微波辐射损伤效应的机制特点,对近年来微波辐射损伤防护药物的研究进展进行综述,为更加安全有效的新药研发提供依据。     

Establishment of injury models in studies of biological effects induced by microwave radiation

Microwave radiation has been widely used in various fields,such as communication,industry,medical treatment,and military applications.Microwave radiation may cause injuries to both the structures and functions of various organs,such as the brain,heart,reproductive organs,and endocrine organs,which endanger human health.Therefore,it is both theoretically and clinically important to conduct studies on the biological effects induced by microwave radiation.The successful establishment of injury models is of great importance to the reliability and reproducibility of these studies.In this article,we review the microwave exposure conditions,subjects used to establish injury models,the methods used for the assessment of the injuries,and the indicators implemented to evaluate the success of injury model establishment in studies on biological effects induced by microwave radiation.     

Pulsed electric field increases reproduction

Purpose To study the effect of pulsed electric field – applied in corona discharge photography – on Drosophila melanogaster reproduction, possible induction of DNA fragmentation, and morphological alterations in the gonads.

Materials and methods Animals were exposed to different field intensities (100, 200, 300, and 400?kV/m) during the first 2–5 days of their adult lives, and the effect on reproductive capacity was assessed. DNA fragmentation during early- and mid-oogenesis was investigated by application of the TUNEL (Terminal deoxynucleotide transferase dUTP Nick End Labeling) assay. Sections of follicles after fixation and embedding in resins were observed for possible morphological/developmental abnormalities.

Results The field increased reproduction by up to 30% by increasing reproductive capacity in both sexes. The effect increased with increasing field intensities. The rate of increase diminished at the strongest intensities. Slight induction of DNA fragmentation was observed exclusively in the nurse (predominantly) and follicle cells, and exclusively at the two most sensitive developmental stages, i.e., germarium and predominantly stage 7–8. Sections of follicles from exposed females at stages of early and mid-oogennesis other than germarium and stages 7–8 did not reveal abnormalities.

Conclusions (1) The specific type of electric field may represent a mild stress factor, inducing DNA fragmentation and cell death in a small percentage of gametes, triggering the reaction of the animal’s reproductive system to increase the rate of gametogenesis in order to compensate the loss of a small number of gametes. (2) The nurse cells are the most sensitive from all three types of egg chamber cells. (3) The mid-oogenesis checkpoint (stage 7–8) is more sensitive to this field than the early oogenesis one (germarium) in contrast to microwave exposure. (4) Possible therapeutic applications, or applications in increasing fertility, should be investigated.     

Sterilization of bone allografts by microwave and gamma radiation

Abstract

Purpose: Bone allografts are used to enhance healing in osteotomies, arthrodesis, fractures and to replace bone loss resulting from tumour or trauma. However, a major concern associated with the bone allografts is the potential for disease transmission. Various sterilization techniques have been developed to prevent infection through allografts. This study was undertaken with the aim of exploring the use of microwave radiation for sterilization of bone allografts and to compare with gamma radiation sterilization.

Materials and methods: Bone allografts were processed from femoral heads obtained from living donors. The effect of microwave and gamma radiation on the bacteria isolated from bone allograft was evaluated. The microwave radiation treatment was performed at 2450 MHz (frequency) for varying lengths of time at maximum power 900 Watts (W). Viability of three Gram-positive bacteria – Bacillus subtilis, Corynebacterium, Staphylococcus aureus and three Gram-negative bacteria – Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa was examined after irradiation of bacterial suspensions and contaminated processed bone allografts. The sterility test of microwave and gamma irradiated bone allograft was carried out in accordance with ISO (International Organization for Standardization) 11737-2.

Results: Microwave irradiation (2450 MHz and 900 W) of bacterial isolates resulted in complete inactivation within 60 seconds. The contaminated bone samples showed no growth of organisms after 2 minutes of exposure to microwave irradiation. No viable counts were detected in bone grafts inoculated with Gram-negative bacterial species on gamma irradiation to a dose of 15 kGy. Bones contaminated with Gram-positive bacteria required a higher dose of 20 kGy for complete inactivation.

Conclusions: The study shows that sterilization of contaminated femoral head bone allografts can be achieved by short exposure of 2 min to 2450 MHz and 900 W microwave radiation.     

阿的平对微波辐射小鼠海马损伤的保护作用

目的探讨预先给予阿的平（quinacrine）对微波辐射致小鼠脑损伤的保护作用。方法小鼠随机分为4组,即正常组、辐射对照组、阿的平低剂量组（12.6 mg/kg）、阿的平高剂量组（50.4 mg/kg）。接受辐射动物于照射后即刻（0 d）,1,2,7 d后完成检测,正常组动物在辐射实验后7 d后完成检测。微波辐照后,于不同时间点提取小鼠的脑组织蛋白,检测脑组织中HSP70蛋白表达变化。结果脑组织蛋白表达检测显示,微波辐射后1 d,辐射对照组小鼠脑中HSP70蛋白的表达开始升高,直至7 d。阿的平两个剂量组0,1,7 d给药组与辐射对照组相比明显上调,高剂量组尤甚。辐射对照组小鼠大脑海马的病理切片显示细胞水肿、血管扩张肿胀、间质充血等损伤,并出现海马沟回组织松散、细胞核皱缩、细胞水肿、空泡现象。预先灌胃给予小鼠阿的平后,小鼠脑组织的病理损伤有所减轻,状况有所改善。结论阿的平的这些保护机制可能与其上调HSP70蛋白表达发挥抗炎和抗凋亡作用,降低微波辐照引起的组织、细胞炎症反应和凋亡、坏死有关。     

高功率微波辐照对大鼠卵巢显微和亚显微结构的影响

目的：研究高功率微波(high power microwave，HPM)对大鼠卵巢组织显微和亚显微结构的影响。方法：健康成年雄性SD大鼠65只，随机分为实验组和对照组(5只)。以S波段平均功率密度分别为20，40和80mW／cm^2的HPM辐照实验组大鼠，辐照时间分别为1，5，10和20min。于辐照后6h取材，应用光镜和透射电镜观察其病理形态变化。结果：光镜下，与对照组相比，从40mW／cm^2 5min亚组开始出现组织水肿、充血和炎细胞浸润，10min亚组开始见卵泡细胞分离明显，20min亚组及80mW／cm^2 1min亚组，5min亚组和10min亚组出现卵泡内层细胞变性，发育不同阶段的卵泡发生卵泡闭锁。黄体细胞发生凋亡。20min亚组则出现组织出血和部分内层细胞坏死崩解。随照射功率密度增加照射时间延长上述病理变化更明显。透射电镜下超微结构发生轻度线粒体水肿、内质网扩张，间质内炎细胞浸润是从40mW／cm^2 5min亚组开始，随照射时间延长，功率密度增加，各组均可见生殖细胞发生变性、凋亡改变；80mW／cm^2 20min亚组可见卵母细胞内次级溶酶体增多，微绒毛发生肿胀。间质细胞凋亡、裂解。20mW／cm^2各亚组，40mW／cm^2 1min亚组及对照组无改变。结论：HPM可导致大鼠卵巢发生明显的病理性改变，当达到80mW／cm^2辐照20min对大鼠卵巢组织有致死效应。