Pub Date : 2020-02-21DOI: 10.4236/ojbiphy.2020.102006
S. Ayrapetyan
At present, there are relevant scientific materials on the cellular and molecular mechanisms of electrogenic Na/K pump function and structure, as well as on the potential- and ligand-activated ionic channels in the membrane. However, the role of electrogenic Na/K pump in regulation of semipermeable properties of cell membrane has not been elucidated yet, which is due to the fact that our knowledge about the biophysical properties of cell membrane is based on the conductive membrane theory of Hodgkin-Huxley-Katz, which is developed on internally perfused squid axon and lacks intracellular metabolism. Thus, the accumulated abundance of data on the role of G-proteins-dependent intracellular signaling system in regulation of Na/K pump activity and biophysical properties of cell membrane presumes fundamental revision of some statements of membrane theory. The aim of the present review is to briefly demonstrate our and literature data on cell hydration-induced auto-regulation of Na/K pump as well as on its role in metabolic control of semipermeable properties and excitability of neuronal membrane, which are omitted in the study of internally perfused squid axon.
{"title":"The Quantum-Mechanical Sensitive Na/K Pump Is a Key Mechanism for the Metabolic Control of Neuronal Membrane Function","authors":"S. Ayrapetyan","doi":"10.4236/ojbiphy.2020.102006","DOIUrl":"https://doi.org/10.4236/ojbiphy.2020.102006","url":null,"abstract":"At present, there are relevant scientific materials on the cellular and molecular mechanisms of electrogenic Na/K pump function and structure, as well as on the potential- and ligand-activated ionic channels in the membrane. However, the role of electrogenic Na/K pump in regulation of semipermeable properties of cell membrane has not been elucidated yet, which is due to the fact that our knowledge about the biophysical properties of cell membrane is based on the conductive membrane theory of Hodgkin-Huxley-Katz, which is developed on internally perfused squid axon and lacks intracellular metabolism. Thus, the accumulated abundance of data on the role of G-proteins-dependent intracellular signaling system in regulation of Na/K pump activity and biophysical properties of cell membrane presumes fundamental revision of some statements of membrane theory. The aim of the present review is to briefly demonstrate our and literature data on cell hydration-induced auto-regulation of Na/K pump as well as on its role in metabolic control of semipermeable properties and excitability of neuronal membrane, which are omitted in the study of internally perfused squid axon.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42180515","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}
Pub Date : 2020-02-21DOI: 10.4236/ojbiphy.2020.102008
K. W. Wong, P. Fung, W. Chow
The coronavirus structure is explained as a fractal representation of the Poincare sphere of proteins, dotted with t-spikes having the geometric realization of the SU(3) Lie group for the protein spike, and encompasses an RNA of SU(2) topologies representations, while within the core contains a virus DNA. Through this suggested model, the virus must possess a critical temperature Tc, induced by the EEM mechanism for the completion of the Poincare sphere surface. Thus above Tc it will disintegrate. We then discuss how the virus transmission progresses within the patient’s body, and explain a very fast recent detection method currently used consistent with this model, as well as a corresponding possible cure based on this same principle of the body’s immune system. Hopefully the model can be also used as a guide to finding possible medications, so far is lacking.
{"title":"COVID-19: A Physical Model","authors":"K. W. Wong, P. Fung, W. Chow","doi":"10.4236/ojbiphy.2020.102008","DOIUrl":"https://doi.org/10.4236/ojbiphy.2020.102008","url":null,"abstract":"The coronavirus structure is explained as a fractal representation of the Poincare sphere of proteins, dotted with t-spikes having the geometric realization of the SU(3) Lie group for the protein spike, and encompasses an RNA of SU(2) topologies representations, while within the core contains a virus DNA. Through this suggested model, the virus must possess a critical temperature Tc, induced by the EEM mechanism for the completion of the Poincare sphere surface. Thus above Tc it will disintegrate. We then discuss how the virus transmission progresses within the patient’s body, and explain a very fast recent detection method currently used consistent with this model, as well as a corresponding possible cure based on this same principle of the body’s immune system. Hopefully the model can be also used as a guide to finding possible medications, so far is lacking.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42374606","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}
{"title":"A Short Note on Containment Scheme against Spreading of Novel Coronavirus COVID-19","authors":"W. Chow, C. Chow","doi":"10.4236/ojbiphy.2020.102007","DOIUrl":"https://doi.org/10.4236/ojbiphy.2020.102007","url":null,"abstract":"A two-stage containment scheme is proposed to minimize spreading of the novel coronavirus. Two stages of quarantine each of 14 days will be involved.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41583662","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}
Pub Date : 2020-01-16DOI: 10.4236/ojbiphy.2020.101003
L. J. Gagliardi, D. Shain
Nanoscale electrostatics plays important roles in aster (spindle) assembly and motion, nuclear envelope breakdown and reassembly, and in force generation at kinetochores, poles, and chromosome arms for prometaphase, metaphase, and anaphase—A chromosome motions during mitosis. A large body of experimental evidence also suggests a role for electrostatics as the trigger for mitosis, which is considered here particularly in the context of cancer. Cancer cells are characterized by impaired intercellular electrical communication and adhesive contact as well as a loss of contact inhibition, conditions associated with increased cell surface negativity relative to their normal counterparts. Dividing cells have also been associated with lower transmembrane potentials and altered intracellular ionic concentrations. Here we propose that cancer cells are distinguished by abnormal trans- and intramembrane electric potentials, leading to the loss of active Na+/K+ plasma membrane pumping, increased intracellular concentrations of sodium and other ions, and alkaline nucleo-cytoplasmic pH, all of which are associated with and integral to carcinogenesis.
{"title":"Electrostatic Contributions to Carcinogenesis","authors":"L. J. Gagliardi, D. Shain","doi":"10.4236/ojbiphy.2020.101003","DOIUrl":"https://doi.org/10.4236/ojbiphy.2020.101003","url":null,"abstract":"Nanoscale electrostatics plays important roles in aster (spindle) assembly and motion, nuclear envelope breakdown and reassembly, and in force generation at kinetochores, poles, and chromosome arms for prometaphase, metaphase, and anaphase—A chromosome motions during mitosis. A large body of experimental evidence also suggests a role for electrostatics as the trigger for mitosis, which is considered here particularly in the context of cancer. Cancer cells are characterized by impaired intercellular electrical communication and adhesive contact as well as a loss of contact inhibition, conditions associated with increased cell surface negativity relative to their normal counterparts. Dividing cells have also been associated with lower transmembrane potentials and altered intracellular ionic concentrations. Here we propose that cancer cells are distinguished by abnormal trans- and intramembrane electric potentials, leading to the loss of active Na+/K+ plasma membrane pumping, increased intracellular concentrations of sodium and other ions, and alkaline nucleo-cytoplasmic pH, all of which are associated with and integral to carcinogenesis.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43879765","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}
Pub Date : 2020-01-16DOI: 10.4236/ojbiphy.2020.101002
A. Nikoghosyan, Lilia Narinyan, Armenuhi Heqimyan, S. Ayrapetyan
Previously we have shown that nM ouabain-induced activation of cAMP-dependent Na/Ca exchange in reverse (R) mode in cell membrane has age-dependent weakening hydration effect on heart muscle and brain tissues and such Na/Ca exchange is characterized by quantum mechanical sensitivity. As in biological experiments radioactive 45Ca is used for the study of cold 40Ca exchange in cells and organisms, in the present work, the age-dependent effect of physiological solution (PS) containing either 40Ca or 45Ca on tissue hydration in different experimental conditions was studied in order to evaluate the bioequivalence of these two forms of Ca. The obtained data indicate that the intraperitoneal injections of 40Ca PS and 45Ca PS leading to activation of RNa/40Ca and RNa/45Ca exchanges, respectively, have different age-dependent effects on heart muscle and brain tissue hydration. As in myocyte membrane, the Na/Ca exchange is more expressed than in neuronal membrane, the age-dependent heart muscle hydration is more sensitive to quantum properties of Ca than brain tissue hydration. The [45Ca]i, in contrary to [40Ca]i, has age-dependent weakening and stabilizing effect on tissue hydration and makes the latter insensitive to ouabain. The obtained data bring us to a strong conclusion that RNa/Ca exchange has quantum mechanical properties and in biological experiments radioactive 45Ca cannot be used for adequate estimation of the functional activity of 40Ca ions in cells and organisms.
在此之前，我们已经证明了nM - w - abain诱导的camp依赖性Na/Ca交换在细胞膜上的反向(R)模式激活对心肌和脑组织具有年龄依赖性的弱化水化作用，并且这种Na/Ca交换具有量子力学敏感性。由于在生物实验中，放射性的45Ca被用于研究细胞和生物体中的冷40Ca交换，在本工作中，研究了不同实验条件下含有40Ca和45Ca的生理溶液(PS)对组织水化的年龄依赖性，以评价这两种Ca的生物等效性。所得数据表明，腹腔注射40Ca PS和45Ca PS分别激活RNa/40Ca和RNa/45Ca交换，对心肌和脑组织水化具有不同的年龄依赖性。正如在肌细胞膜中，Na/Ca交换比在神经元膜中表达得更多，年龄依赖性心肌水化比脑组织水化对Ca的量子特性更敏感。与[40Ca]i相反，[45Ca]i对组织水化具有年龄依赖性的弱化和稳定作用，使后者对瓦巴因不敏感。得到的数据使我们得出一个强有力的结论，RNa/Ca交换具有量子力学性质，在生物实验中，放射性45Ca不能用于充分估计细胞和生物体中40Ca离子的功能活性。
{"title":"The Radioactive 45Ca Cannot Be Used for Adequate Estimation of the Functional Activity of 40Ca Ions in Cells and Organisms","authors":"A. Nikoghosyan, Lilia Narinyan, Armenuhi Heqimyan, S. Ayrapetyan","doi":"10.4236/ojbiphy.2020.101002","DOIUrl":"https://doi.org/10.4236/ojbiphy.2020.101002","url":null,"abstract":"Previously we have shown that nM ouabain-induced activation of cAMP-dependent Na/Ca exchange in reverse (R) mode in cell membrane has age-dependent weakening hydration effect on heart muscle and brain tissues and such Na/Ca exchange is characterized by quantum mechanical sensitivity. As in biological experiments radioactive 45Ca is used for the study of cold 40Ca exchange in cells and organisms, in the present work, the age-dependent effect of physiological solution (PS) containing either 40Ca or 45Ca on tissue hydration in different experimental conditions was studied in order to evaluate the bioequivalence of these two forms of Ca. The obtained data indicate that the intraperitoneal injections of 40Ca PS and 45Ca PS leading to activation of RNa/40Ca and RNa/45Ca exchanges, respectively, have different age-dependent effects on heart muscle and brain tissue hydration. As in myocyte membrane, the Na/Ca exchange is more expressed than in neuronal membrane, the age-dependent heart muscle hydration is more sensitive to quantum properties of Ca than brain tissue hydration. The [45Ca]i, in contrary to [40Ca]i, has age-dependent weakening and stabilizing effect on tissue hydration and makes the latter insensitive to ouabain. The obtained data bring us to a strong conclusion that RNa/Ca exchange has quantum mechanical properties and in biological experiments radioactive 45Ca cannot be used for adequate estimation of the functional activity of 40Ca ions in cells and organisms.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43051763","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}
Pub Date : 2020-01-01DOI: 10.4236/ojbiphy.2020.101001
L. Gasparyan, I. Mazo, V. Simonyan, F. Gasparyan
The results of comparative theoretical analyzes of the behavior of internal low-frequency noises, signal-to-noise ratio and sensitivity to DNA molecules for EIS and ISFET based nanosize biosensors are presented. It is shown that EIS biosensor is more sensitive to the presence of DNA molecules in aqueous solution than ISFET sensor. Internal electrical noises level decreases with the increase of concentration of DNA molecules in aqueous solution. In the frequency range 10−3 - 103 Hz noises level for EIS sensor about in three orders is higher than for ISFET sensor. In the other hand, signal-to-noise ratio for capacitive EIS biosensor is much higher than for ISFET sensor.
{"title":"Noises and Signal-to-Noise Ratio of Nanosize EIS and ISFET Biosensors","authors":"L. Gasparyan, I. Mazo, V. Simonyan, F. Gasparyan","doi":"10.4236/ojbiphy.2020.101001","DOIUrl":"https://doi.org/10.4236/ojbiphy.2020.101001","url":null,"abstract":"The results of comparative theoretical analyzes of the behavior of internal low-frequency noises, signal-to-noise ratio and sensitivity to DNA molecules for EIS and ISFET based nanosize biosensors are presented. It is shown that EIS biosensor is more sensitive to the presence of DNA molecules in aqueous solution than ISFET sensor. Internal electrical noises level decreases with the increase of concentration of DNA molecules in aqueous solution. In the frequency range 10−3 - 103 Hz noises level for EIS sensor about in three orders is higher than for ISFET sensor. In the other hand, signal-to-noise ratio for capacitive EIS biosensor is much higher than for ISFET sensor.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70618420","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}
Pub Date : 2019-09-29DOI: 10.4236/ojbiphy.2019.94019
N. Abuhadi, Ali Bakry Abdoelrahman Hassan
Many factors contribute to the accuracy of delivered dose to patients in external-beam radiotherapy (EBRT). Although some of these factors can be checked by implementing suitable quality control procedures, the main aim was to assess the radiotherapy treatment filed on portal film using image processing technique in order to increase the accuracy of treatment delivery to the tumor by measuring the actual F/S, dose uniformity and penumbra size using portal film. This research is conducted at radiation therapy department, Khartoum Oncology Center (RICK), Khartoum state, Sudan, from July-2014 up to December-2014. The field size of each type of radiotherapy Co60 is measured as (9.4 × 9.4) cm and (9.1 × 9.1) cm, for linear accelerator machines it was 10 × 10 cm exactly as the reference field size, and there is no area reduced in linacs. The penumbra size for the two types of Co60 machine was measured also and it was 1.2 cm and 1.0 cm, and penumbra size of the linear accelerator machines was found to be 4 mm. The area of the field that received radiation by 100% was measured and it was 94.1% and 91.1% in Co60 and 100% for linear accelerator machine and that means linacs deliver the 100% of the dose to the useful field size. The dose percentage in the field for Co60 was 98.0% and 94.1% and thus the dose in the border of field 83.1% and 89.0% and it’s different in linacs because the dose percentage in the field was 78.4% and 78.4% and there is no measurable dose outside its field. Penumbra Co60 machines are relatively large which increase radiation dose to normal tissue and reduce the TCP, so calculation and accuracy of such calculation are necessary to the patient in term of NTCP.
{"title":"Assessment of Radiotherapy Treatment Field on Portal Film Using Image Processing","authors":"N. Abuhadi, Ali Bakry Abdoelrahman Hassan","doi":"10.4236/ojbiphy.2019.94019","DOIUrl":"https://doi.org/10.4236/ojbiphy.2019.94019","url":null,"abstract":"Many factors contribute to the accuracy of delivered dose to patients in external-beam radiotherapy (EBRT). Although some of these factors can be checked by implementing suitable quality control procedures, the main aim was to assess the radiotherapy treatment filed on portal film using image processing technique in order to increase the accuracy of treatment delivery to the tumor by measuring the actual F/S, dose uniformity and penumbra size using portal film. This research is conducted at radiation therapy department, Khartoum Oncology Center (RICK), Khartoum state, Sudan, from July-2014 up to December-2014. The field size of each type of radiotherapy Co60 is measured as (9.4 × 9.4) cm and (9.1 × 9.1) cm, for linear accelerator machines it was 10 × 10 cm exactly as the reference field size, and there is no area reduced in linacs. The penumbra size for the two types of Co60 machine was measured also and it was 1.2 cm and 1.0 cm, and penumbra size of the linear accelerator machines was found to be 4 mm. The area of the field that received radiation by 100% was measured and it was 94.1% and 91.1% in Co60 and 100% for linear accelerator machine and that means linacs deliver the 100% of the dose to the useful field size. The dose percentage in the field for Co60 was 98.0% and 94.1% and thus the dose in the border of field 83.1% and 89.0% and it’s different in linacs because the dose percentage in the field was 78.4% and 78.4% and there is no measurable dose outside its field. Penumbra Co60 machines are relatively large which increase radiation dose to normal tissue and reduce the TCP, so calculation and accuracy of such calculation are necessary to the patient in term of NTCP.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48252942","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}
Pub Date : 2019-08-26DOI: 10.4236/ojbiphy.2019.94018
Victoria L. Hossack, M. Persinger, B. Dotta
A multitude of experiments have applied magnetic fields to plants or seeds and found a variety of different and sometimes contradicting results. A magnetic field generating device called the Chrysalis resonator has been shown to influence the brain activity of human participants, the photon emissions from bacteria, mammalian cell cultures and water. In this experiment sunflower seeds (Helianthus annus) were allowed to begin germination and then exposed to either the field generated by the Chrysalis resonator or a sham condition. Their growth and photon emissions were taken over the next 5 days. It was found that the seeds showed less germination 48 hours after exposure and significantly higher photon emissions when 3 seeds were measured together in a dish, but not if 2 seeds or 1 seed were measured. There were no significant differences in the photon measurements from the water the seeds were germinating in. These results may indicate that the seeds became more sensitive to the presence of neighbouring seeds. The photon emissions results were also significantly impacted by external weather conditions.
{"title":"Seed Germination and Their Photon Emission Profile Following Exposure to a Rotating Magnetic Field","authors":"Victoria L. Hossack, M. Persinger, B. Dotta","doi":"10.4236/ojbiphy.2019.94018","DOIUrl":"https://doi.org/10.4236/ojbiphy.2019.94018","url":null,"abstract":"A multitude of experiments have applied magnetic fields to plants or seeds and found a variety of different and sometimes contradicting results. A magnetic field generating device called the Chrysalis resonator has been shown to influence the brain activity of human participants, the photon emissions from bacteria, mammalian cell cultures and water. In this experiment sunflower seeds (Helianthus annus) were allowed to begin germination and then exposed to either the field generated by the Chrysalis resonator or a sham condition. Their growth and photon emissions were taken over the next 5 days. It was found that the seeds showed less germination 48 hours after exposure and significantly higher photon emissions when 3 seeds were measured together in a dish, but not if 2 seeds or 1 seed were measured. There were no significant differences in the photon measurements from the water the seeds were germinating in. These results may indicate that the seeds became more sensitive to the presence of neighbouring seeds. The photon emissions results were also significantly impacted by external weather conditions.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41417955","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}
Pub Date : 2019-08-26DOI: 10.4236/ojbiphy.2019.94017
L. Gasparyan, I. Mazo, V. Simonyan, F. Gasparyan
Dependency of both source-drain current and current sensitivity of nanosize ISFET biosensor vs. concentration of DNA molecules in aqueous solution theoretically is investigated. In calculations it is carried out effects concerning charge carriers distribution in current channel and concerning carriers’ mobility behavior in high electrical fields in the channel. The influence of DNA molecules on the work of ISFET biosensors is manifested by a change in the magnitude of the gate surface charge. Starting with fairly low concentrations of DNA, ISFET sensors respond to the presence of DNA molecules in an aqueous solution which is manifested by modulation of channel conductance and therefore the source-drain current changes of the field-effect transistor. It is shown that the current sensitivity with respect to concentration of DNA molecules linearly depends on the source-drain voltage and reaches high values.
{"title":"ISFET Based DNA Sensor: Current-Voltage Characteristic and Sensitivity to DNA Molecules","authors":"L. Gasparyan, I. Mazo, V. Simonyan, F. Gasparyan","doi":"10.4236/ojbiphy.2019.94017","DOIUrl":"https://doi.org/10.4236/ojbiphy.2019.94017","url":null,"abstract":"Dependency of both source-drain current and current sensitivity of nanosize ISFET biosensor vs. concentration of DNA molecules in aqueous solution theoretically is investigated. In calculations it is carried out effects concerning charge carriers distribution in current channel and concerning carriers’ mobility behavior in high electrical fields in the channel. The influence of DNA molecules on the work of ISFET biosensors is manifested by a change in the magnitude of the gate surface charge. Starting with fairly low concentrations of DNA, ISFET sensors respond to the presence of DNA molecules in an aqueous solution which is manifested by modulation of channel conductance and therefore the source-drain current changes of the field-effect transistor. It is shown that the current sensitivity with respect to concentration of DNA molecules linearly depends on the source-drain voltage and reaches high values.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44159392","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}
Pub Date : 2019-05-21DOI: 10.4236/OJBIPHY.2019.93011
A. Yakubu, Z. Abbas, Z. Yunusa
Brain tissue plays a significant role in both cognitive and psychomotor behavior of humans. However, their interaction with radiation emanating from hand held mobile devices is still not fully understood. This research was aimed at investigating radiation absorption in brain tissue. Bovine brain tissues ranging from lesser than 1 year to greater than 10 years of age were bought from a specialty store (Sigma-Aldrich). The tissues were used within 72 h of extraction for ex vivo brain experiments. The brain tissue was stored at 6°C and then 16°C for 24 h in the MRI room to reach thermal equilibrium before any experiments were undertaken. The averages for the dielectric constant were measured from 1 - 4 GHz using open ended coaxial probe (OECP) (85,070E; Agilent Technologies). The results obtained for the dielectric properties were then used as raw data in the numerical computation and simulation of the radiation absorption by the brain tissues for both adolescent and adults bovine brain tissue using finite element method (FEM). The measured dielectric constants varied for the different brain tissue from 54.39 to 39.29. Analysis showed that adolescents tissue absorbed more radiation than adults from mobile phoneradiation which is due to the higher dielectric property of adolescent brain tissue. The results obtained can be applied to human brain tissue since bovine shares the same compositional properties with humans.
{"title":"Easy Determination of Radiation Absorption in Brain Tissue from Mobile Phones Using Finite Element Method","authors":"A. Yakubu, Z. Abbas, Z. Yunusa","doi":"10.4236/OJBIPHY.2019.93011","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2019.93011","url":null,"abstract":"Brain tissue plays a significant role in both cognitive and psychomotor behavior of humans. However, their interaction with radiation emanating from hand held mobile devices is still not fully understood. This research was aimed at investigating radiation absorption in brain tissue. Bovine brain tissues ranging from lesser than 1 year to greater than 10 years of age were bought from a specialty store (Sigma-Aldrich). The tissues were used within 72 h of extraction for ex vivo brain experiments. The brain tissue was stored at 6°C and then 16°C for 24 h in the MRI room to reach thermal equilibrium before any experiments were undertaken. The averages for the dielectric constant were measured from 1 - 4 GHz using open ended coaxial probe (OECP) (85,070E; Agilent Technologies). The results obtained for the dielectric properties were then used as raw data in the numerical computation and simulation of the radiation absorption by the brain tissues for both adolescent and adults bovine brain tissue using finite element method (FEM). The measured dielectric constants varied for the different brain tissue from 54.39 to 39.29. Analysis showed that adolescents tissue absorbed more radiation than adults from mobile phoneradiation which is due to the higher dielectric property of adolescent brain tissue. The results obtained can be applied to human brain tissue since bovine shares the same compositional properties with humans.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45028029","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}
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