Bioelectrochemistry and bioenergetics (Lausanne, Switzerland)最新文献_第10页

The zero potential and Wilson's central terminal in electrocardiography 心电图中的零电位和威尔逊中心终端

Bioelectrochemistry and bioenergetics (Lausanne, Switzerland) Pub Date : 1998-12-01 DOI: 10.1016/S0302-4598(98)00201-3

Yoshiwo Okamoto , Saburo Mashima

引用次数: 6

Thermochemiluminescence as a technique for radio frequency radiation dosimetry 热化学发光技术在射频辐射剂量测定中的应用

Bioelectrochemistry and bioenergetics (Lausanne, Switzerland) Pub Date : 1998-12-01 DOI: 10.1016/S0302-4598(98)00196-2

Johnathan L. Kiel, John L. Alls, Eric A. Holwitt, Lucille J.V. Stribling, Jill E. Parker

{"title":"Thermochemiluminescence as a technique for radio frequency radiation dosimetry","authors":"Johnathan L. Kiel, John L. Alls, Eric A. Holwitt, Lucille J.V. Stribling, Jill E. Parker","doi":"10.1016/S0302-4598(98)00196-2","DOIUrl":"10.1016/S0302-4598(98)00196-2","url":null,"abstract":"<div>Radio frequency radiation (RFR) dosimetry is based on the rate of absorbed energy (specific absorption rate: SAR) per unit mass. It is most conveniently measured by acquiring changes in temperature per unit time and converting the results to joules per second (watts) per kilogram, based on the specific heat of the biological material interacting with the RFR. To date, SAR has been predicted by modeling based on the dielectric properties of tissues, or measured by infrared (IR) thermography or with macroscopic high-resistance thermistors or thermofluorescent macroscopic point probes. Thermochemiluminescence (TCL) was invented to provide a high degree of continuous spatial and temporal thermal resolution in phantoms. It is defined as the steady-state emission of visible light from a peroxidizing mixture based on the temperature of the mixture. The best material for this purpose, to date, is diazoluminomelanin (DALM). Unfortunately, standardization of the synthesis (chemical composition) of this polymer and its thermal response constant (thermal quantum efficiency) has been difficult. This paper presents a biosynthetic method for the large-scale production of the polymer and a computational method for directly determining the SAR from the luminescence.</div>","PeriodicalId":79804,"journal":{"name":"Bioelectrochemistry and bioenergetics (Lausanne, Switzerland)","volume":"47 2","pages":"Pages 253-257"},"PeriodicalIF":0.0,"publicationDate":"1998-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0302-4598(98)00196-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80010676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

The effect of plasmid DNA sizes and other factors on electrotransformation of Escherichia coli JM109 质粒DNA大小等因素对大肠杆菌JM109电转化的影响

Bioelectrochemistry and bioenergetics (Lausanne, Switzerland) Pub Date : 1998-12-01 DOI: 10.1016/S0302-4598(98)00203-7

Monika Szostková, Dana Horáková

引用次数: 29

Cultivation of cells under strong ac-electric field—differentiation between heating and trans-membrane potential effects 培养细胞在强交流电场作用下的分化加热和跨膜电位效应

Bioelectrochemistry and bioenergetics (Lausanne, Switzerland) Pub Date : 1998-12-01 DOI: 10.1016/S0302-4598(98)00146-9

H. Glasser, G. Fuhr

{"title":"Cultivation of cells under strong ac-electric field—differentiation between heating and trans-membrane potential effects","authors":"H. Glasser, G. Fuhr","doi":"10.1016/S0302-4598(98)00146-9","DOIUrl":"10.1016/S0302-4598(98)00146-9","url":null,"abstract":"<div>Adherently growing mouse fibroblasts were cultivated for days in highly conductive culture media between micro-fabricated electrodes under strong ac-electric fields. Miniature electrodes have improved heat dissipation which allows the use of media with conductivity of more than 1 S/m at field strengths of up to 100 kV/m. Cell division rates, cell motility, cell viability and physiological parameters such as vesiculation were monitored and the actin and β-tubuline structures of cyto-skeleton were imaged by laser scanning fluorescence. The specific effects of polarisation could be differentiated from unspecific effects such as heating. We estimated the real field strength acting on cells. In the kHz-range, field application was clearly limited by membrane dielectric breakdown while temperature increases were less than 3°C. In the MHz-range, much stronger fields could be applied and heating became the limiting factor. Above an induced trans-membrane potential of 130–150 mV cells no longer proliferated under prolonged field application. In the MHz-range (above 5 MHz) cells could be exposed to surprisingly high field strengths (40 kV/m) for days. Therefore, there is a frequency window (up to several 100 MHz) which can be used for cell positioning, manipulation and characterisation techniques without significant loading of cells.</div>","PeriodicalId":79804,"journal":{"name":"Bioelectrochemistry and bioenergetics (Lausanne, Switzerland)","volume":"47 2","pages":"Pages 301-310"},"PeriodicalIF":0.0,"publicationDate":"1998-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0302-4598(98)00146-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85899126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 58

On the fetal magnetocardiogram 在胎儿心脏磁图上

Bioelectrochemistry and bioenergetics (Lausanne, Switzerland) Pub Date : 1998-12-01 DOI: 10.1016/S0302-4598(98)00199-8

M.J. Peters , J.G. Stinstra , S.P. van den Broek , J.A.F. Huirne , H.W.F. Quartero , H.J.M. ter Brake , H. Rogalla

{"title":"On the fetal magnetocardiogram","authors":"M.J. Peters , J.G. Stinstra , S.P. van den Broek , J.A.F. Huirne , H.W.F. Quartero , H.J.M. ter Brake , H. Rogalla","doi":"10.1016/S0302-4598(98)00199-8","DOIUrl":"10.1016/S0302-4598(98)00199-8","url":null,"abstract":"<div>Fetal magnetocardiography is a non-invasive technique for studying the electrical activity of the fetal heart. Fetal magnetocardiograms (fMCG) can be used to diagnose and classify fetal cardiac arrhythmias reliably. An averaged fMCG shows a QRS-complex, a P-wave, and a T-wave. However, it is still unknown if the currents in the tissues surrounding the fetal heart disturb these features. Furthermore, the measuring technique is not yet optimised for fMCG registrations. Simulation studies may provide guidelines for the design of an appropriate magnetometer system. Therefore, finite-element and boundary-element models were constructed in order to study the possible influence of the volume conductor. Especially, the influence of the layer of vernix caseosa, a fatty layer that covers the fetus, was investigated. The computations showed that the layer of vernix caseosa will affect the waveform of the fMCG. The signal processing procedure used is also discussed. It turned out to be difficult to deduce the onset and offset of the T-wave from the resulting averaged signals. Possibly, the QRS-complex does not provide a correct trigger to obtain a distinguishable T-wave in the averaged signal, because the RT-interval may be variable.</div>","PeriodicalId":79804,"journal":{"name":"Bioelectrochemistry and bioenergetics (Lausanne, Switzerland)","volume":"47 2","pages":"Pages 273-281"},"PeriodicalIF":0.0,"publicationDate":"1998-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0302-4598(98)00199-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86111893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Calculation of energy absorption in a human body model in a homogeneous pulsed high-frequency field 均匀脉冲高频场中人体模型能量吸收的计算

Bioelectrochemistry and bioenergetics (Lausanne, Switzerland) Pub Date : 1998-12-01 DOI: 10.1016/S0302-4598(98)00192-5

Dina Šimunić

引用次数: 7

Field-induced electroconformational damages in cell membrane proteins: a new mechanism involved in electrical injury 电场诱导细胞膜蛋白的电构象损伤:一种涉及电损伤的新机制

Bioelectrochemistry and bioenergetics (Lausanne, Switzerland) Pub Date : 1998-12-01 DOI: 10.1016/S0302-4598(98)00194-9

Wei Chen, Yu Han, Yan Chen, Jing Tian Xie

{"title":"Field-induced electroconformational damages in cell membrane proteins: a new mechanism involved in electrical injury","authors":"Wei Chen, Yu Han, Yan Chen, Jing Tian Xie","doi":"10.1016/S0302-4598(98)00194-9","DOIUrl":"10.1016/S0302-4598(98)00194-9","url":null,"abstract":"<div>Mechanisms of electrical injury may involve electrical and thermal phenomena. These factors affect cell membranes and membrane proteins. Results of the stress of these factors include permeabilization of the cell membranes and dysfunctions of the membrane proteins, especially the voltage-sensitive membrane proteins. In this paper, we discussed mechanisms involved in damaging the K+ channel proteins. We show that the level of channel damage is not directly correlated to the shock field-induced huge channel currents, therefore not to the thermal damages in the proteins. Instead, the channel damages are dependent on the field-induced supramembrane potential (magnitude and polarity). Moreover, the number of limiting charge particles which function as the voltage-sensor in the channel gating system was reduced after a supramembrane potential shock. These results indicate that a supramembrane potential shock may cause electroconformational changes in the membrane proteins, which may reveal a new mechanism involved in electrical injury. Moreover, these studies also provide evidence that external electric fields can be used to modify functions of the voltage-sensitive membrane proteins by electrical coupled conformational changes in the proteins.</div>","PeriodicalId":79804,"journal":{"name":"Bioelectrochemistry and bioenergetics (Lausanne, Switzerland)","volume":"47 2","pages":"Pages 237-245"},"PeriodicalIF":0.0,"publicationDate":"1998-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0302-4598(98)00194-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76969487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15

A model for the detection of weak ELF electric and magnetic fields 弱极低频电场和磁场的探测模型

Bioelectrochemistry and bioenergetics (Lausanne, Switzerland) Pub Date : 1998-12-01 DOI: 10.1016/S0302-4598(98)00190-1

Frank S Barnes

引用次数: 1

Interaction of low level modulated RF radiation with Na+–K+-ATPase 低水平调制射频辐射与Na+ -K +- atp酶的相互作用

Bioelectrochemistry and bioenergetics (Lausanne, Switzerland) Pub Date : 1998-12-01 DOI: 10.1016/S0302-4598(98)00195-0

J Behari, K.K Kunjilwar, S Pyne

{"title":"Interaction of low level modulated RF radiation with Na+–K+-ATPase","authors":"J Behari, K.K Kunjilwar, S Pyne","doi":"10.1016/S0302-4598(98)00195-0","DOIUrl":"10.1016/S0302-4598(98)00195-0","url":null,"abstract":"<div>The effect of low-level amplitude modulated radiofrequency radiation were studied on Na+–K+-ATPase activity in the brain of developing male Wistar rats of age 23 days (body weight 55–60 g). They were exposed to carrier wave (CW) frequency 147 MHz and its sub-harmonic frequencies 73.5 and 36.75 MHz amplitude modulated (AM) at 16 and 76 Hz for 30–35 days (3 h day−1, Power density 1.47 mW cm−2,average specific absorption rate 9.65–6.11 W kg−1). We observed a statistically significant increase in Na+–K+-ATPase activity in chronically exposed rats compared to the control ones. The increase in Na+–K+-ATPase activity was around 19–20% in the rats exposed to CW frequencies AM at 16 Hz compared to the controls, whereas the increase in Na+–K+-ATPase activity was around 15–16% in rats exposed to the same set of CW frequencies but AM at 76 Hz. Though there was a difference in Na+–K+-ATPase activities (3–4%) in the two groups but the difference was found to be statistically insignificant. Within the group of rats exposed to CW frequencies amplitude modulated at 16 and 76 Hz, respectively, the effect on Na+–K+-ATPase activity was found to be independent of the magnitude of CW frequencies. An additional single short duration (20–60 min) exposure of membranes in vitro from different exposed group to the above field did not show any significant alteration on Na+–K+-ATPase activity. It is concluded that a low level effect of amplitude modulated radiation produces statistically significant effect on Na+–K+-ATPase activity but is insensitive to the carrier wave frequencies under investigation.</div>","PeriodicalId":79804,"journal":{"name":"Bioelectrochemistry and bioenergetics (Lausanne, Switzerland)","volume":"47 2","pages":"Pages 247-252"},"PeriodicalIF":0.0,"publicationDate":"1998-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0302-4598(98)00195-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85788991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 20

Functional magnetic stimulation: theory and coil optimization 功能磁刺激:理论与线圈优化

Bioelectrochemistry and bioenergetics (Lausanne, Switzerland) Pub Date : 1998-12-01 DOI: 10.1016/S0302-4598(98)00191-3

Jarmo Ruohonen , Paolo Ravazzani , Ferdinando Grandori

引用次数: 20