Department

     Academic Staff

• Prof.Dr. Nesrin SEYHAN (Head of the Department)

• Assist.Prof.Dr.Ayşe G. CANSEVEN

• Assist.Prof.Göknur Güler ÖZTÜRK

• Dr.Bahriye SIRAV

• Dr. Arın TOMRUK

•  

RESEARCH

Department of Biophysics

Bioelectromagnetic Laboratory

Medical Faculty of Gazi University

"Biological Effects of Electric and Magnetic Fields" are being evaluated at the two sub research laboratories, BIOELECTROMAGNETICS LABORATORY and TISSUE ANALYSIS LABORATORY, in the Department of Biophysics.

In Bioelectromagnetic Laboratory the research activities are based on the biological effects of electromagnetic fields from the devices mainly used in our daily life. In Tissue Analysis Laboratory, the protein synthesis is being analyzed with two different methods.

Research activities in these laboratories:

• Low Intensity Direct Current (LIDC) Application on Skin Wounds
• Evaluation of Hydroxyproline quantity on skin: Woessner Method
• Application of Magnetic Fields (B) on Biological Systems
• Application of Electric Fields (E) on Biological Systems
• Evaluation of Hydroxyproline quantity on tissue: Stegemann-Stalder Method
• Dosimetry
• Electromagnetic (EM) Pollution
• Standards on Non-ionizing Radiation (ICNIRP, IEEE, FCC, CENELEC, Italy, Canada and China)
• Biological Effects of ELF E and B fields
• Biological Effects of RF/MW fields
• Standards of EM Radiation Measurement

 FINDINGS

ELF MAGNETIC FIELDS (B);

Decreases found in;

·        NK (Natural Killer) cytotoxic activity in spleen cells,

·        Zn⁺⁺ and K⁺ concentration in plasma,

Increases found in;

·        Ca⁺⁺, Na⁺ and Mg⁺⁺ concentration in plasma,

·        the levels of Zn⁺⁺, Cu⁺⁺, Ca⁺⁺ and Mg⁺⁺ in brain,

have no effects on epileptic seizures, have effects on collagen synthesis in skin relating with field intensity and application time

Low Intensity Direct Currents (LIDC) have been induced healing of wounds,

DC (DIRECT CURRENT) AND ELF (EXTREMELY LOW FREQUENCY) ELECTRIC (E) FIELDS;

have been found effective on hydroxyproline, malondialdehyde, structural changes in bone and liver tissue, radical production, superoxide dismutase (SOD) enzyme activity in liver, lung, skin and kidney tissues, alkaline phosphatase, lactate dehydrogenase, piruvat transferase and gama glutamly transferase enzyme activities, total protein and albumin quantities, calcium, chlorine and phosphorus levels in blood;  histopathologic structure and mechanical properties in bone tissues.

In Bioelectromagnetic Laboratory, Theoretical Dosimetric studies have also been executed. Electric fields and current densities induced by external E and B fields of 50 Hz are evaluated by Dosimetry studies. Functionally equivalent exposure parameters of human is being estimated from the animal exposure examples.

GRADUATE

MedIcal Faculty / 2^nd Year / BIOPHYSICS (56 HOURS/YEAR)

Aim:      The main goal is to introduce the students with Cell, Tissue, Circulation, Metabolism and Neuroendocrine Biophysics with encouraging them on putting question marks AND TRYING TO FİND THE ANSWERS.

CELL AND TISSUE BIOPHYSICS ( 20 hours )

- Membrane: structure and electrical properties

·         Membrane as a capacitor, electric field of membrane, membrane capacitance

- Cell: Electrical properties, electrical equivalence models of the cell and the membrane

- Reason to the biological potential difference:  Asymmetry

- Stimulation with electric current, Injury Current

- Calculation of cell potential: Nernst, Goldman-Hodgkin-Katz and Hodgkin-Huxley modellings, evaluation of the ion currents of cell using Kirchoff’s rule

- Voltage-Clamp: Evaluation technique of ion currents of membrane

- Electromagnetic (EM) energy and interaction of Electromagnetic Fields (EMF) with tissue

·         Sonic characteristics of tissue

·         Production of ultrasound and the piezoelectric phenomenon

·         Characteristic Impedance: Characteristic Impedance of tissues

·         Absorption of Ultrasound by tissues: Factors effective on the absorption

·         Penetration of ultrasound to the tissue and frequency dependence

·         Ultrasound's cavitation effect and the role in medicine

·         Ultrasound's heat effect and the role in medicine

·         Ultrasound in diagnosis, therapy and surgery

·         Doppler Ultrasound

·         Infrasound

·         Piezoelectric structures in tissues; bone

·         Healing of bone fractures with electric currents, invasive and non-invasive techniques

·         Biomaterials and implant corrosion in tissues

·         Bioceramics and Bioglass Implants

CIRCULATION BIOPHYSICS (  20 hours )

- Blood Viscosity and factors effective on viscosity

- Flow, cross-section area and velocity relations in blood vessels

- Ohm's Law in Circulation: Relations between pressure, current and resistance

- Forces affecting eritrosits: Stoke's law

- Pressure in Circulation system: Bernoulli's Law

- Velocity and flow   in internal frictional flow: Poiseuille's Law

- Kinetic energy factor in vessels

- Laminar and turbulant flows

- Exercises

- Variations in Pressure - Velocity and Kinetic Energy factors as a result of pathological narrowing in the arteries 

- Volume - Pressure relation in arteries and veins, Total Pheripheric resistance

- Fahreus - Lindqvist Effect

- Resistance in series and parallel blood vessel systems

- Laplace Law and authoregulation of pressure

- Energy loss in blood circulation as a result of friction

- Blood flow and measurement techniques of blood pressure: Pitot tubes

- Electromagnetic and Ultrasonic Flowmeters

BIOPHYSICS OF METABOLISM (  9 hours )

- System: Energy in Biological systems and Metabolic Rate

- Thermodynamic systems, enthalpy and entropy: Open, closed and isolated systems and human body

- Regulation of heat and transfer mechanisms: Heat transfer with Conduction, Convection and Radiation

- Fourier's and Newton's Heat Releasing Laws

- Molar evaporation heat, specific heat and heat capacity

- Thermogram

BIOPHYSICS OF NEUROENDOCRINE (  8 hours )

- Electric and magnetic fields of Human Body: Heart's, abdomen's and brain's magnetic properties

- Brain potentials and electrical activity of brain

- Electroencephalogram: a, b, delta, teta waves and properties of these waves

- Invasive and non-invasive techniques in Brain imaging: MEG, CAT, PET, MRI

- Sound and physical properties of the sound

- Anatomy and Biophysics of the Hearing System

·         Middle Ear: Structure and biological pressure amplification

·         Internal ear: Structure, Resonance in Membrana Basilaris; Endococlear Potential and Corti as a transducer, Helmholtz Resonance Theory

PROJECTS

Thesis Projects

Master of Science Thesis

• CANSEVEN A.: Low Intensity Direct Current (LIDC) Effect on Collagen Synthesis in Wound Healing, Master Thesis (Supervisor : Prof. Dr. Nesrin Seyhan), Gazi University Institute of Medical Sciences, Biophysics Dept., Ankara (1993) (Turkish).

• GÜLER G.: Electric Field Effect on Tissue Hydroxyproline Level, Master Thesis (Supervisor : Prof. Dr. Nesrin Seyhan), Gazi University Institute of Medical Sciences, Biophysics Dept., Ankara (1994) (Turkish).

• SIRAV B.: Radio Frequency Radiation Sources, Standards / Guidelines of Countries and International Organizations, Turkey’s Situation, Radiation Calculation of a Pilot Region, Master Thesis (Supervisor: Prof. Dr. Nesrin SEYHAN), Gazi University, Institute of Medical Sciences, Biophysics Dept., Ankara (2001) (Turkish).

• FIRLARER A. : ETA Measurements for 900 MHz Cellular Base Stations in Residental Areas and ETA Pollution Charts, Master Thesis (Supervisor: Prof. Dr. Nesrin SEYHAN), Gazi University, Institute of Medical Sciences, Biophysics Dept., Ankara (2003) (Turkish).

PhD Thesis

• GÜLER G.: AC Electric Field Effect on Protein Synthesis with Different Application Times, PhD Thesis (Supervisor : Prof. Dr. Nesrin Seyhan), Gazi University Institute of Medical Sciences, Biophysics Dept., Ankara (1998) (Turkish).

• CANSEVEN A.: Changes in Hydroxyproline Levels of Skin under the Effects of Magnetic Fields with Different Intensities and Different Exposure Periods, PhD Thesis (Supervisor : Prof. Dr. Nesrin Seyhan), Gazi University Institute of Medical Sciences, Biophysics Dept., Ankara (1998) (Turkish).

Ongoing Projects

·       Foundation of “Electromagnetic Pollution Measurement Center”, Gazi University, Scientific Research Project, (TF.31/2002-07)
2002-…

·       Construction of “Radio Frequency Experiment System”, Gazi University, Scientific Research Project, (TF.01/2003-62)

      2003-…