生物物理学期刊(英文)最新文献_第5页

The Quantum-Mechanical Sensitive Na/K Pump Is a Key Mechanism for the Metabolic Control of Neuronal Membrane Function 量子力学敏感钠钾泵是神经元膜功能代谢调控的关键机制

生物物理学期刊(英文) Pub Date : 2020-02-21 DOI: 10.4236/ojbiphy.2020.102006

S. Ayrapetyan

{"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":" ","pages":""},"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}

引用次数: 3

COVID-19: A Physical Model COVID-19:一个物理模型

生物物理学期刊(英文) Pub Date : 2020-02-21 DOI: 10.4236/ojbiphy.2020.102008

K. W. Wong, P. Fung, W. Chow

引用次数: 5

A Short Note on Containment Scheme against Spreading of Novel Coronavirus COVID-19 关于新型冠状病毒COVID-19防控方案的简要说明

生物物理学期刊(英文) Pub Date : 2020-02-21 DOI: 10.4236/ojbiphy.2020.102007

W. Chow, C. Chow

引用次数: 4

Electrostatic Contributions to Carcinogenesis 静电对致癌的作用

生物物理学期刊(英文) Pub Date : 2020-01-16 DOI: 10.4236/ojbiphy.2020.101003

L. J. Gagliardi, D. Shain

引用次数: 0

The Radioactive 45Ca Cannot Be Used for Adequate Estimation of the Functional Activity of 40Ca Ions in Cells and Organisms 放射性的45Ca不能用于充分估计细胞和生物体中40Ca离子的功能活性

生物物理学期刊(英文) Pub Date : 2020-01-16 DOI: 10.4236/ojbiphy.2020.101002

A. Nikoghosyan, Lilia Narinyan, Armenuhi Heqimyan, S. Ayrapetyan

{"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":" ","pages":""},"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}

引用次数: 1

Noises and Signal-to-Noise Ratio of Nanosize EIS and ISFET Biosensors 纳米EIS和ISFET生物传感器的噪声和信噪比

生物物理学期刊(英文) Pub Date : 2020-01-01 DOI: 10.4236/ojbiphy.2020.101001

L. Gasparyan, I. Mazo, V. Simonyan, F. Gasparyan

引用次数: 1

Assessment of Radiotherapy Treatment Field on Portal Film Using Image Processing 应用图像处理技术评估门脉膜放射治疗场

生物物理学期刊(英文) Pub Date : 2019-09-29 DOI: 10.4236/ojbiphy.2019.94019

N. Abuhadi, Ali Bakry Abdoelrahman Hassan

{"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":" ","pages":""},"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}

引用次数: 0

Seed Germination and Their Photon Emission Profile Following Exposure to a Rotating Magnetic Field 旋转磁场下种子发芽及其光子发射谱

生物物理学期刊(英文) Pub Date : 2019-08-26 DOI: 10.4236/ojbiphy.2019.94018

Victoria L. Hossack, M. Persinger, B. Dotta

引用次数: 0

ISFET Based DNA Sensor: Current-Voltage Characteristic and Sensitivity to DNA Molecules 基于ISFET的DNA传感器：电流-电压特性和对DNA分子的敏感性

生物物理学期刊(英文) Pub Date : 2019-08-26 DOI: 10.4236/ojbiphy.2019.94017

L. Gasparyan, I. Mazo, V. Simonyan, F. Gasparyan

引用次数: 5

Easy Determination of Radiation Absorption in Brain Tissue from Mobile Phones Using Finite Element Method 用有限元法简单测定手机对脑组织的辐射吸收

生物物理学期刊(英文) Pub Date : 2019-05-21 DOI: 10.4236/OJBIPHY.2019.93011

A. Yakubu, Z. Abbas, Z. Yunusa

{"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":" ","pages":""},"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}

引用次数: 2