生物电磁学研究进展

生物电磁学(Bioelectromagnetics)是一门关于电磁学与生物学、医学相互渗透的边缘交叉学科。工频电磁场与癌症,特别是儿童白血病发病率的关系、移动电话是否会促进肿瘤的发生、生物体对电磁场的响应、作用到生物体的电磁场剂量的确定方法、制定电磁环境安全卫生标准、地球电磁环境的     

人体电磁兼容系统与电磁场处理水——Ⅲ．电磁水对人体电磁场的作用

《人体电磁兼容系统与电磁场处理水》一分三篇写。第一篇“Ⅰ.人体电磁兼容系统”,讨论了人体体内电磁场;第二篇“Ⅱ.电磁水的特性”,讨论了电磁水的电磁场。二均已发表于《生物磁学》。本是第三篇,讨论电磁水电磁场对人体电磁场的作用,重点阐明饮用电磁水后,主要是电磁水的电磁场作为入射场与体内场发生迭加作用,产生耦合电磁场,从而实现其对体内场的调节作用,达到维系身体健康的目的。由于有关水的问题非常复杂,动态性强,故大多数关于耦合场的研究均服从于“统计学规律”。     

生物电磁学研究进展

生物电磁学(Bioelectromagnetics)是一门关于电磁学与生物学、医学相互渗透的边缘交叉学科。工频电磁场与癌症,特别是儿童白血病发病率的关系、移动电话是否会促进肿瘤的发生、生物体对电磁场的响应、作用到生物体的电磁场剂量的确定方法、制定电磁环境安全卫生标准、地球电磁环境的变迁及其对生物进化的影响、生物体内电磁场及生物组织电磁性质的测定和电磁场在生物医学中的应用等等,都是生物电磁学研究的课题。生物电磁学就是研究从直流电到远红外的电场、磁场和电磁场与生物系统相互作用的科学。电磁波包括短波、高频波(例如X射线、γ射…     

人体电磁兼容系统与电磁场处理水--Ⅲ.电磁水对人体电磁场的作用

《人体电磁兼容系统与电磁场处理水》一文分三篇写。第一篇“Ⅰ.人体电磁兼容系统”,讨论了人体体内电磁场;第二篇“Ⅱ·电磁水的特性”,讨论了电磁水的电磁场。二文均已发表于《生物磁学》。本文是第三篇,讨论电磁水电磁场对人体电磁场的作用,重点阐明饮用电磁水后,主要是电磁水的电磁场作为入射场与体内场发生迭加作用,产生耦合电磁场,从而实现其对体内场的调节作用,达到维系身体健康的目的。由于有关水的问题非常复杂,动态性强,故大多数关于耦合场的研究均服从于“统计学规律”。     

磁场对微循环影响的研究进展

磁场的生物学效应是磁场和生物体两者共同作用的结果,是与两者的参数密切相关的.磁场参数包括磁场类型,场强大小,作用时间等,这些参数是影响磁场生物学效应的主要因素.磁生物学是研究不同的外加磁场对不同种类和不同层次生物结构单元的生物学效应及其作用机制的科学.电磁场对生物膜的离子转运能力的影响会导致机体一些生化和生理过程的变化,从而影响与生物电活动相关的各种过程.本文概述了近年磁场对微循环影响的研究成果.     

电磁场暴露海马神经元自由基和胞内Ca2+的变化

电磁场对健康影响的研究包括流行病调查、人体与动物、细胞、生化与分子生物、生物物理等5个层次,电磁生物效应最初是通过物理作用产生化学反应,继而产生后续生物反应.自由基、电磁能量和生物钙是分属于化学、物理学和生物学的3个概念,研究它们之间的关系对于认识电磁生物效应的原初作用具有意义.选择海马神经元,观察在0.1mT、0.5mT和1.0mT电磁场暴露48h,海马神经元ROS水平和胞内Ca2+浓度的变化.实验结果表明:暴露于0.1mT,0.5mT和1.0mT电磁场海马神经元的ROS水平和Ca2+浓度都比对照组有显著性提高(P<0.01).暴露于0.1mT和0.5mT电磁场的ROS水平和暴露于0.1mT电磁场的Ca2+浓度与自由基清除剂+电磁场(Trolox+EMF)组比较没有差异(P>0.05),暴露于1.0mT电磁场的ROS水平和暴露于0.5mT和1.0mT电磁场的Ca2+浓度比Trolox+EMF组有显著性提高(P<0.01).表明电磁场可以促进细胞自由基的产生,并且ROS水平与胞内Ca2+浓度有正相关性.     

人体电磁兼容系统与电磁场处理水-Ⅰ.人体电磁兼容系统

“人体电磁兼容系统与电磁场处理水”是一篇综论,分为:.人体电磁兼容系统,.电磁水(电磁场处理过的水)的特性,.电磁水对人体电磁场的作用,三部份。本文是该篇综论文章的第一部份,首先阐明地球表层生物圈的电磁现象,分析存在着生命的大环境就是一个“地球电磁谐振腔”;尔后,剖析从蛋白质,到生物大分子、细胞与细胞膜、器官组织,直到人体的电磁因子与电磁现象,说明人体内部也存在一个电磁场,即“生物电磁场”;最后则顺理成章,通过“生命的慢节律制式”实现人体内、外电磁环境的“并存”,归结为“内外电磁环境的兼容”,表明“人体是一美妙复杂的电磁兼容系统。”人,是自然界的一部份,自然界的电磁理论同样也适用于人体。     

人体电磁兼容系统与电磁场处理水——Ⅰ．人体电磁兼容系统

“人体电磁兼容系统与电磁场处理水”是一篇综论,分为：．人体电磁兼容系统,．电磁水(电磁场处理过的水)的特性,．电磁水对人体电磁场的作用,三部份。本文是该篇综论文章的第一部份,首先阐明地球表层生物圈的电磁现象,分析存在着生命的大环境就是一个“地球电磁谐振腔”;尔后,剖析从蛋白质,到生物大分子、细胞与细胞膜、器官组织,直到人体的电磁因子与电磁现象,说明人体内部也存在一个电磁场,即“生物电磁场”;最后则顺理成章,通过“生命的慢节律制式”实现人体内、外电磁环境的“并存”,归结为“内外电磁环境的兼容”,表明“人体是一美妙复杂的电磁兼容系统。”人,是自然界的一部份,自然界的电磁理论同样也适用于人体。     

河口缺氧生物效应研究进展

世界许多河口都存在季节性缺氧的现象,并且低氧出现的频率、范围、持续时间、强度都有明显上升的趋势,因此河口缺氧引起的生态效应受到人们越来越多的关注.河口生物种类繁多,根据它们的运动能力和栖息环境的不同可分为浮游生物、游泳生物和底栖生物.河口缺氧不仅影响河口生物的分布与生存,而且还会改变群落结构、影响生态系统的结构与功能.从分子、群落和生态系统等不同层次综述了河口缺氧生物效应的研究进展,并提出了展望与建议.     

纳米二氧化钛的生物学效应

纳米二氧化钛在国内外的研究与应用已经非常广泛．在涂料、颜料、陶瓷、化妆等方面的应用与人体有密切的接触。由于物质在纳米尺度会产生很多宏观尺度所不具有的特殊效应,在宏观尺度被证实无毒无害的二氧化钛,当被制备到纳米尺度时,对人体的作用是否仍然安全,这个问题已引起一部分科学研究工作者的关注。该文简要介绍与纳米二氧化钛生物效应相关的一些特性;纳米二氧化钛毒性,包括纳米二氧化钛的渗透性、体内急性毒性、细胞毒性,以及对DNA的损伤等。目前国内外对纳米二氧化钛的毒性机制研究尚处在一个猜测性的阶段,其中对蛋白质、氨基酸等生物大分子作用的研究仍是一个空白。     

New mechanisms of biological effects of electromagnetic fields

ATP production in mitochondria depends on the nuclear spin and magnetic moment of Mg²⁺ ion in creatine kinase and ATPase. Consequently, the enzymatic synthesis of ATP is an ion-radical process and depends on the external magnetic field and microwave fields that control the spin states of ion-radical pairs and influence the ATP synthesis. The chemical mechanism of ATP synthesis and the origin of biological effects of electromagnetic (microwave) fields are discussed.     

Influence of electromagnetic radiation on molecular solitons

The soliton model of charge and energy transport in biological macromolecules is used to suggest one of the possible mechanisms for electromagnetic radiation influence on biological systems. The influence of the electromagnetic field (EMF) on molecular solitons is studied both analytically and numerically. Numerical simulations prove the stability of solitons for fields of large amplitude, and allow the study of emission of phonons. It is shown that in the spectra of biological effects of radiation there are two characteristic frequencies of EMFs, one of which is connected with the most intensive energy absorption and emission of sound waves by the soliton, and the other of which is connected with the soliton photodissociation into a delocalized state.     

Electromagnetic homeostasis and the role of low-amplitude electromagnetic fields on life organization

The appearance of endogenous electromagnetic fields in biological systems is a widely debated issue in modern science. The electrophysiological fields have very tiny intensities and it can be inferred that they are rapidly decreasing with the distance from the generating structure, vanishing at very short distances. This makes very hard their detection using standard experimental methods. However, the existence of fast-moving charged particles in the macromolecules inside both intracellular and extracellular fluids may envisage the generation of localized electric currents as well as the presence of closed loops, which implies the existence of magnetic fields. Moreover, the whole set of oscillatory frequencies of various substances, enzymes, cell membranes, nucleic acids, bioelectrical phenomena generated by the electrical rhythm of coherent groups of cells, cell-to-cell communication among population of host bacteria, forms the increasingly complex hierarchies of electromagnetic signals of different frequencies which cover the living being and represent a fundamental information network controlling the cell metabolism. From this approach emerges the concept of electromagnetic homeostasis: that is, the capability of the human body to maintain the balance of highly complex electromagnetic interactions within, in spite of the external electromagnetic noisy environment. This concept may have an important impact on the actual definitions of heal and disease.     

Molecular change signal-to-noise criteria for interpreting experiments involving exposure of biological systems to weakly interacting electromagnetic fields

We describe an approach to aiding the design and interpretation of experiments involving biological effects of weakly interacting electromagnetic fields that range from steady (dc) to microwave frequencies. We propose that if known biophysical mechanisms cannot account for an inferred, underlying molecular change signal-to-noise ratio, (S/N)gen, of a observed result, then there are two interpretation choices: (1) there is an unknown biophysical mechanism with stronger coupling between the field exposure and the ongoing biochemical process, or (2) the experiment is responding to something other than the field exposure. Our approach is based on classical detection theory, the recognition that weakly interacting fields cannot break chemical bonds, and the consequence that such fields can only alter rates of ongoing, metabolically driven biochemical reactions, and transport processes. The approach includes both fundamental chemical noise (molecular shot noise) and other sources of competing chemical change, to be compared quantitatively to the field induced change for the basic case that the field alters a single step in a biochemical network. Consistent with pharmacology and toxicology, we estimate the molecular dose (mass associated with field induced molecular change per mass tissue) resulting from illustrative low frequency field exposures for the biophysical mechanism of voltage gated channels. For perspective, we then consider electric field-mediated delivery of small molecules across human skin and into individual cells. Specifically, we consider the examples of iontophoretic and electroporative delivery of fentanyl through skin and electroporative delivery of bleomycin into individual cells. The total delivered amount corresponds to a molecular change signal and the delivery variability corresponds to generalized chemical noise. Viewed broadly, biological effects due to nonionizing fields may include animal navigation, medical applications, and environmental hazards. Understanding necessary conditions for such effects can be based on a unified approach: quantitative comparison of the estimated chemical change due to a particular electromagnetic field exposure to that due to competing influences, with both estimates based on a biophysical mechanism model within the context of a model of a biological system.     

Biological effects of exposure to magnetic resonance imaging: an overview

The literature on biological effects of magnetic and electromagnetic fields commonly utilized in magnetic resonance imaging systems is surveyed here. After an introduction on the basic principles of magnetic resonance imaging and the electric and magnetic properties of biological tissues, the basic phenomena to understand the bio-effects are described in classical terms. Values of field strengths and frequencies commonly utilized in these diagnostic systems are reported in order to allow the integration of the specific literature on the bio-effects produced by magnetic resonance systems with the vast literature concerning the bio-effects produced by electromagnetic fields. This work gives an overview of the findings about the safety concerns of exposure to static magnetic fields, radio-frequency fields, and time varying magnetic field gradients, focusing primarily on the physics of the interactions between these electromagnetic fields and biological matter. The scientific literature is summarized, integrated, and critically analyzed with the help of authoritative reviews by recognized experts, international safety guidelines are also cited.     

Calcium protects differentiating neuroblastoma cells during 50 Hz electromagnetic radiation

Despite growing concern about electromagnetic radiation, the interaction between 50- to 60-Hz fields and biological structures remains obscure. Epidemiological studies have failed to prove a significantly correlation between exposure to radiation fields and particular pathologies. We demonstrate that a 50- to 60-Hz magnetic field interacts with cell differentiation through two opposing mechanisms: it antagonizes the shift in cell membrane surface charges that occur during the early phases of differentiation and it modulates hyperpolarizing K channels by increasing intracellular Ca. The simultaneous onset of both mechanisms prevents alterations in cell differentiation. We propose that cells are normally protected against electromagnetic insult. Pathologies may arise, however, if intracellular Ca regulation or K channel activation malfunctions.     

Transient effect of weak electromagnetic fields on calcium ion concentration in Arabidopsis thaliana

Background  

Weak magnetic and electromagnetic fields can influence physiological processes in animals, plants and microorganisms, but the underlying way of perception is poorly understood. The ion cyclotron resonance is one of the discussed mechanisms, predicting biological effects for definite frequencies and intensities of electromagnetic fields possibly by affecting the physiological availability of small ions. Above all an influence on Calcium, which is crucial for many life processes, is in the focus of interest. We show that in Arabidopsis thaliana, changes in Ca²⁺-concentrations can be induced by combinations of magnetic and electromagnetic fields that match Ca²⁺-ion cyclotron resonance conditions.     

Low energy pulsing electromagnetic fields modify biomedical processes

Low-energy, pulsed electromagnetic fields (PEMFs) have reversed therapeutically resistant pathologic processes in the musculo-skeletal system. Their development as a non-thermal therapeutic agent is based on 30 years of study of the electro-biological properties of connective tissues. Specific energy characteristics in applied PEMFs produce selected biological effects by modifying synthetic and other behavioral patterns of target cells; some mechanisms of action are defined. The technology appears safe and effective in clinical treatment of un-united fractures, avascular necrosis of bone, and chronic, refractory tendinitis. An expanding, rational use in biomedical science is predicted.     

Simulated biological materials for electromagnetic radiation absorption studies

For the study of electromagnetic dosimetry and hyperthermia, it is necessary to simulate human biological materials. This can be done by chemical mixtures that are described in this paper. Formulas are presented for simulating bone, lung, brain, and muscle tissue in the frequency range of 100 MHz to 1 GHz. By using these preparations a realistic equivalent to the human body can be constructed.