Morphophysiological and Proteomic Responses on Plants of Irradiation with Electromagnetic Waves.

Electromagnetic energy is the backbone of wireless communication systems, and its progressive use has resulted in impacts on a wide range of biological systems. The consequences of electromagnetic energy absorption on plants are insufficiently addressed. In the agricultural area, electromagnetic-wave irradiation has been used to develop crop varieties, manage insect pests, monitor fertilizer efficiency, and preserve agricultural produce. According to different frequencies and wavelengths, electromagnetic waves are typically divided into eight spectral bands, including audio waves, radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. In this review, among these electromagnetic waves, effects of millimeter waves, ultraviolet, and gamma rays on plants are outlined, and their response mechanisms in plants through proteomic approaches are summarized. Furthermore, remarkable advancements of irradiating plants with electromagnetic waves, especially ultraviolet, are addressed, which shed light on future research in the electromagnetic field.

Health effects of radiofrequency electromagnetic energy.

The issues of real or suspected health effects of radiofrequency fields, produced by cellphones, their base stations and many other devices, are complex and controversial. We believe that the most balanced and valid assessments of these issues are given by the extensive reports produced by reputable, multidisciplinary, expert groups. These use the principles of a comprehensive review to assess all available published literature and form their conclusions by consideration of the strength of the evidence from the available studies. This paper provides links to several of these reports, and shows how others can be accessed. These reports are large and complex, but freely available on websites. We summarise the most recent New Zealand report, which itself refers to and summarises many other reports. The scientific literature on these issues is enormous, particularly in animal and laboratory studies. There are some comprehensive reviews of these, demonstrating that the quality of the studies is very variable, and that, for example, results claiming to show increased genetic damage or other biological effects are much more common in studies of low quality, whereas higher-quality studies predominantly show no significant effects. Thus, while there are many reports which in isolation suggest health effects, there is no consistent evidence supporting important health effects caused by low intensities of radiofrequencies similar to those experienced by the general population. There are certainly many unanswered questions, and new studies need to be assessed carefully and replicated where possible. Thus, expert groups in several countries including New Zealand need to continue to regularly review new studies.

[Radiosensitivity of morphoenzymological structural elements of the jejunum mucous membrane in chronodynamics of the impact of electromagnetic fields impulses].

Results of numerous researches have revealed that most sensitive to electromagnetic radiations are the nervous, endocrine and cardiovascular systems of an organism, however, the analysis of literary data confirms also the direct involvement of organs of the intestinal system in physiological, and not seldom, and the pathological program of the response of an organism to the action of extreme factors. In the experiment executed on white laboratory male rats by ourselves there was studied the grade of the radiosensitivity of morphoenzymological structural elements of jejunum mucous membrane after 5, 7 and 10 months of chronic influence of electromagnetic fields impulses with a density of induced currents 0.37; 0.7; 0.8; 2.7 kA/m and frequency of impulses 50, 100 and 500 in a week irrespective of their divisibility of ultrashort duration of 15 a 40 ns. Scientific value and novelty of results is concluded in revealed multiple linear relationships between indices of electromagneticfields (duration of the impact, density of induced currents, periodicity of impulses and the dynamics of the studied indices of a morphofunctional condition of a jejunum mucous membrane). Besides that, there was found the critical population to indices of electromagneticfields impulses parameters - the jejunum mast cells differing in hypersensitivity and dependence on duration of influence and density of induced currents revealed, at that their bioeffects were unidirectional.

Ascending-ramp biphasic waveform has a lower defibrillation threshold and releases less troponin I than a truncated exponential biphasic waveform.

BACKGROUND: We tested the hypothesis that the shape of the shock waveform affects not only the defibrillation threshold but also the amount of cardiac damage. METHODS AND RESULTS: Defibrillation thresholds were determined for 11 waveforms-3 ascending-ramp waveforms, 3 descending-ramp waveforms, 3 rectilinear first-phase biphasic waveforms, a Gurvich waveform, and a truncated exponential biphasic waveform-in 6 pigs with electrodes in the right ventricular apex and superior vena cava. The ascending, descending, and rectilinear waveforms had 4-, 8-, and 16-millisecond first phases and a 3.5-millisecond rectilinear second phase that was half the voltage of the first phase. The exponential biphasic waveform had a 60% first-phase and a 50% second-phase tilt. In a second study, we attempted to defibrillate after 10 seconds of ventricular fibrillation with a single ≈30-J shock (6 pigs successfully defibrillated with 8-millisecond ascending, 8-millisecond rectilinear, and truncated exponential biphasic waveforms). Troponin I blood levels were determined before and 2 to 10 hours after the shock. The lowest-energy defibrillation threshold was for the 8-milliseconds ascending ramp (14.6±7.3 J [mean±SD]), which was significantly less than for the truncated exponential (19.6±6.3 J). Six hours after shock, troponin I was significantly less for the ascending-ramp waveform (0.80±0.54 ng/mL) than for the truncated exponential (1.92±0.47 ng/mL) or the rectilinear waveform (1.17±0.45 ng/mL). CONCLUSIONS: The ascending ramp has a significantly lower defibrillation threshold and at ≈30 J causes 58% less troponin I release than the truncated exponential biphasic shock. Therefore, the shock waveform affects both the defibrillation threshold and the amount of cardiac damage.

A comprehensive study of channel estimation for WBAN-based healthcare systems: feasibility of using multiband UWB.

Wireless personal area network (WPAN) is an emerging in wireless technology for short range indoor and outdoor communication applications. A more specific category of WPAN is the wireless body area network (WBAN) used for health monitoring. On the other hand, multiband orthogonal frequency division multiplexing (MB-OFDM) ultra-wideband (UWB) comes with a number of desirable features at the physical layer for wireless communications, for example, very high data rate. One big challenge in adoption of multiband UWB in WBAN is the fact that channel estimation becomes difficult under the constraint of extremely low transmission power. Moreover, the heterogeneous environment of WBAN causes a dense multipath wireless channel. Therefore, effective channel estimation is required in the receiver of WBAN-based healthcare system that uses multiband UWB. In this paper, we first outline the MB-OFDM UWB system. Then, we present an overview of channel estimation techniques proposed/investigated for multiband UWB communications with emphasis on their strengths and weaknesses. Useful suggestions are given to overcome the weaknesses so that these methods can be particularly useful for WBAN channels. Also, we analyze the comparative performances of the techniques using computer simulation in order to find the energy-efficient channel estimation methods for WBAN-based healthcare systems.

Interacciones de las radiaciones electromagnéticas y especies reactivas del oxígeno sobre la piel / Interactions of electromagnetic radiations and reactive oxygen species on skin

La energía radiante abarca todo el espectro electromagnético y proviene de la fusión en el sol, de 4 núcleos de hidrógeno en uno de helio. Las radiaciones electromagnéticas tienen características de ondas, con la velocidad de la luz (c) y difieren en sus longitudes de ondas (λ). La energía lumínica es transmitida en unidades individuales o fotones: E = h c/λ así, los fotones de menores λs son los de mayor energía. Las radiaciones ultravioletas (UV) (λs de 200 - 400 nm) pueden dividirse: UVA (λs 315 - 400 nm); UVB (λs 280 - 315 nm) y UVC (λs < 280 nm). UVB y UVC son las más importantes, en inducir respuestas biológicas. Por acción de las radiaciones electromagnéticas el O2, da productos agrupados bajo la denominación de Especies Reactivas del Oxígeno (ROS). El alto contenido de O2 en los sistemas biológicos estimula la formación de ROS, que si no son controladas por el sistema endógeno de antioxidantes, afectan el estado redox de las células y generan daños tisulares ("stress oxidativo"). Inducen peroxidación de lípidos, entrecruzamiento de proteínas, inhibición de enzimas, pérdida de integridad y función de membranas plasmáticas y mitocondriales, ruptura de organelas intracelulares. Como consecuencias producen inflamación, envejecimiento, carcinogénesis y muerte celular. Mientras las radiaciones infrarrojas, inducen aumento de la temperatura cutánea, llegando a producir graves quemaduras, las UVA y UVB, en forma encubierta, reaccionan con cromóforos del tejido cutáneo, que absorben fotones y generan alteraciones fotoquímicas, implicadas en el envejecimiento celular e inducción de cáncer. La radiación UV al alcanzar el núcleo de las células causa daños en el ADN. Los seres humanos debemos protegernos de los efectos deletéreos del sol que representa un problema de salud pública, de suma importancia. Defensa que logramos con la vestimenta y uso de productos protectores de la piel. Las bacterias, así como otros procariotas, más expuestas a las radiaciones solares han generado plásmidos, que incrementan por medio de un sistema de reparación del ADN, la tolerancia a la UV y otros agentes mutagénicos.

The energy of electromagnetic radiation is derived from the fusion in the sun of four hydrogen nuclei to form a helium nucleus. The sun radiates energy representing the entire electromagnetic spectrum. Light is a form of electromagnetic radiation. All electromagnetic radiation has wave characteristics and travels at the same speed (c: speed of light). But radiations differ in wavelength (λ). Light energy is transmitted not in a continuum stream but only in individual units or photons: E = h c/λ. Short wave light is more energetic than photons of light of longer wavelength. Ultraviolet radiations (UV) (λs 200 - 400 nm) can be classified in UVA (λs 315 - 400 nm.); UVB (λs 280 - 315 nm) and UVC (λs < 280 nm). UVB and UVC are the most significant UV radiations to induce biological responses. Electromagnetic radiations on molecular oxygen lead to several reactive products known as Reactive Oxygen Species (ROS). High O2 content in biological systems promotes ROS synthesis. If ROS are not controlled by endogenous antioxidants, cell redox status is affected and tissue damage is produced ("oxidative stress"). ROS induce lipid peroxidation, protein cross-linking, enzyme inhibition, loss of integrity and function of plasmatic and mitochondrial membranes conducing to inflammation, aging, carcinogenesis and cell death. While infra-red radiations lead to noticeable tissue temperature conducing to severe burns, UVA and UVB undercover react with skin chromophores producing photochemical alterations involved in cellular aging and cancer induction. As UV radiations can reach cellular nucleus, DNA can be damage. Human beings need protection from the damaging sunbeams. This is a very important concern of public health. While humans need to protect their skin with appropriate clothing and/or by use of skin sunblocks of broad spectrum, some bacteria that are extensively exposed to sunlight have developed genomic evolution (plasmid-encoded DNA repair system) which confer protection from the damaging effect of UV radiation.