the arab journal of scientific researchaiesa.org/wp-content/uploads/2019/05/vol.-2.pdfthe arab...
TRANSCRIPT
The Arab Journal of Scientific Research
Periodical - Scientific - Regional - Court – Specialized
Issued by the Arab Foundation for Education, Science and Arts
Editor
Prof.Eslam Sheha Energy storage (Magnesium battery) Department of Physics,
Faculty of Science Benha University, Egypt
Deposit number at the Egyptian Book House in Cairo
24024 / 2017
License of the Supreme Council for Media Regulation in the Arab Republic of Egypt
VOL. 2 2019
ISSN: 2537-0367
ISSN (Online) : 2537-0375
Editorial Board
EDITORS-IN-CHIEF
1. Prof. Eslam Sheha
Energy storage (Magnesium battery) Department of Physics, Faculty of Science , Benha
University, Egypt
Tel : 002- 0100- 7414705
: 002- 013- 3244487
Fax: 002- 013- 3222578
Website: http://bu.edu.eg/staff/islamshihah7-about
Scholar: https://scholar.google.com/citations?sortby=pubdate&hl=en&user=X1KQBSsAAA
AJ&view_op=list_works
Email: [email protected]
ORCID: http://orcid.org/0000-0002-8700-4906
Researcher ID: http://www.researcherid.com/rid/F-8028-2015
ASSOCIATE EDITORS
2. Prof. Basem Zoheir
Professor (Mineralogy and Economic Geology)
Department of Geology, Faculty of Science,
Benha University, 13518 Benha, Egypt
Tel: +201062792092
Fax: +20133222578
3. Prof. Elham Salama
Entomology Department, Faculty of Science, Benha University, Benha 13518, Egypt
http://bu.edu.eg/staff/elhamsalama7
4. Prof. Khaled SharafEldin
Zoolgy Department, Faculty of Science, Benha University, Benha 13518, Egypt
http://bu.edu.eg/staff/khaledsharafeldein7
5. Dr. Bahaa El-Dien M. El-Gendy
Associate Professor of Bio-Organic Chemistry
Chemistry Department, Faculty of Science, Benha University, Benha 13518, Egypt
Co-chair of the Egyptian Young Academy of Sciences (EYAS)
Elected Member of Global Young Academy, Berlin, Germany
Young Affiliate of The World Academy of Sciences (TWAS)
Phone:+2-01207607583
Fax: +2-0133222578
6. Dr. Radwan Radwan Khalil
Faculty of science benha university
Egypt.
Member of egyptian mission
center of agriculture research
Hungarian academic of science
http://bu.edu.eg/staff/radwanaboelabbas7
7. Dr. Ahmed Farag
Department of Physics,
Faculty of Science, Behna University,
Benha 13518, Qaliubiya, Egypt.
https://scholar.google.com.eg/citations?user=fVCubX8AAAAJ&hl=en
8. Dr. Eman Kamar
Chemistry Department, Faculty of Science, Benha University, Benha 13518, Egypt
http://bu.edu.eg/staff/emanabdelfattah7
9. Dr. Essam Awad
Math Department, Faculty of Science, Benha University, Benha 13518, Egypt
http://bu.edu.eg/staff/essamawad7
10. Dr. Mohamed Elsayed
Math Department, Faculty of Science, Benha University, Benha 13518, Egypt
http://bu.edu.eg/staff/mohamedhassan7
The Arab Journal of Scientific Research
http://aiesa.org/2017/09/the-arab-journal-of-scientific-research/
1
Complex impedance analysis and relationships
with electrical conductivity, and dielectric
constants
Fathy Salman
Physics department, Faculty of Science,Banha University,
Egypt
Introduction
AC impedance spectroscopy is a valuable tool for
studying both the bulk transport properties of a material and
the ac conductivity and the dielectric properties.The
principle of the impedance analysis method is based on
measurements of the sample impedance taken over a wide
range of frequencies and then analysed in the complex
impedance plane . The mathod was firstly applied to solid
electrolytes problems by Bauerle(19)
and then used by many
workers for various superionic conductors. The impedance
analysis method requires the determination from the
measurements two parts of the complex impedance of the
sample Z* = Z' + J Z''. The main parameters Rand C are
deduced from the analysis of impedance method
Theoretical background:
The impedance is defined as the Z is the complex
ratio of the applied (ac) voltage V ( to the
resultant current I( at frequency
I
VZ (1)
The impedance is most directly interpreted when
written in polar form, can be expressed in terms of the
the modulus and the phase angle φ
Z*= V*/ I* = eφ (2)
Where the magnitude represents the ratio of the voltage
difference amplitude to the current amplitude, while the
argument φ gives the phase difference between voltage and
current and j is the imaginary unit.
Using Euler's relationship:
Z* = cosφ + j sinφ (3) The impedance is then expressed as
Z* = Z' + J Z'' (4)
Z' = cosφ (5)
Z'' = sinφ (6)
The main parameters deduced from the analysis of
impedance method are Rand C
In Cartesian form Z* is defined as
Z*= V*/ I* = R + J X (7)
where the real part of impedance is the resistance R and the
imaginary part is the reactance X . In case of a capacitor Zc
=1/jωC i,e. X=XC = (-1/ωc). The capacitor is a result of
the sample’s geometry, while the resistor represents the
resistivity of the bulk This impedance depends on the
frequency and is entirely capacitive.
Z* =R+j(-1/ωC) (8)
From above relations we obtain :
R = Z' (9)
-1/ωC = Z''
C = -1/ ω Z''
(10)
Tan φ = Z’’/ Z’ Or Tanδ =Z’/Z’’ (11)
Table
F
(Hz)
Z
(Ohm)
Q Z'
= cosφ
Z"
= sinφ
C
=1/ωZ''
R
=z’
tan δ
=z’/z’’
- - --
Data Presentation
Complex Impedance Plot
If the real part Z’ is plotted on the x-axis and the imaginary
part Z’’
on the y-axis of a chart, a so called "Nyquist plot," or
complex plane impedance diagram, is revealed. As shown
Fathy Salman
Vol. 2
2
in Figure , this plot has the shape of a semicircle. Notice
that in this plot the y-axis was chosen as negative notation
and that each
Figure 1. Nyquist Plot with Impedance Vector
point on the Nyquist plot is the impedance at one frequency
[1]. On the Nyquist plot the impedance can be represented
as a vector of length| Z |. The angle between this vector and
the x-axis is φ, or "phase angle"which also has a negative
notation, as (from Eq. 1-11):
There is a parameter τ=RC called "time constant,"
which is associated with this circuit, and a corresponding
"characteristic circular" frequency ωc= 1/τ and
"characteristic" or "critical relaxation" frequency. At very
high frequencies the impedance is completely capacitive,
while at low frequencies it becomes completely resistive
and approaches the value of R, which equals the diameter of
the Nyquist plot semicircle. The phase angle φ tends
towards -90° at high frequency and towards 0°at low
frequency, and critical frequency fc corresponds to a
midpoint transition where the phase angle is -45° and Z’ =
Z’’= R/2.The diameter of the semicircle is taken as the bulk
resistance.Then
The Nyquist Plot in Figure 1 results from the electrical
circuit of Figure 2. The semicircle is characteristic of a
single "time constant". Impedance plots often contain
several semicircles. Often only a portion of a semicircle is
seen.
Figure 2. Simple Equivalent Circuit with One Time
Constant
Another popular presentation method is the Bode
Plot. The impedance is plotted with log frequency on the X-
axis and both the absolute values of the impedance (|Z|=Z0)
and the phase-shift on the Y-axis.Unlike the Nyquist Plot,
the Bode Plot does show frequency information.
Ac conductivity (ω) is calculated by using the
relation,
ω
where R is the resistance , (t ) and (a) are the thickness and
the area
Dielectri constant ε' is calculated using the
following relation:
ε' =
where C is the capacitance , t and
a are the thickness and the area.
Dielectric Loss ε'' is calculated using the
following relation:
ε’’
= ε' tan δ
where δ = (90- φ) , φ is the phase angle.
Conclusions
Complex impedance analysis and relationships with electrical conductivity, and dielectric constants
3
The impedance measurements of the sample is taken in
terms of the the modulus and the phase angle φ taken
over a wide range of frequencies. The values of Z’ and Z’’
can be found ,R and C are deduced. Ac conductivity (ω),
dielectri constant ε' and dielectric Loss ε'' are determined.
References
The following sources were used in preparing this
application note
Bauerle J E 1069 J Phys. Chem. Solids 30 2657.
Mackdonald J R (ed) 1987. Impedance spectroscopy
emphasizing solid state materials and systems ( New York
Wiley).
The Equivalent Circuit of Impedance
The simplest model for an electrode – sample system
under an applied voltage is a capacitor and resistor in
parall. Figure a. The capacitor is a result of the sample’s
geometry, while the resistor represents the resistivity of
the bulk.The impedance of such circuit at frequency
consists of the real part R and
and is written as :
The value Z can put in the form ;
Which can be separated into the real part Z` and the
imaginary part Z`` as :
221``
RZ
By ellimainating
(1.11) can be combined and written in the form of a circle :
Z`2
– Z` R + Z
``2 = o
Adding R2/4 to both
sides of equation (1.12) one
obtains
(Z` - ½ R )
2 + Z
``2 = (½ R)
2
Comparing this equation with the standard form of the
equation of a circle , one can see that the Z-plane plot is a
semicircle in the first quadrant with center at (½ R,0) and
with a radius ½ R fig 3.1.b. It can be shown also that at the
maxium of the semicircle
time constant or the relaxation time of the circuit .
Figure ( 1 ) : Complex impedence plot for
the parallel circuit RC .
So, when from the complex impedance measurements
when only one semicircle obtained and this semicircle
originates in the (0,0) point ,it means that only one
resistance R and one capacity c both parallel combined ,
can be described to the sample in such a case, these should
be the bulk resistance and capacity of the sample .
cjRZ
11
RCj
RZ
;
1
122
221`
RZ
Z`` C
R (0,0) R Z
`
RC=
1
(0,1/2R
)
(a
)
(b
)
Fathy Salman
Vol. 2
4
Figure (2,3.4&5 ) : Complex impedence plots for
simple circuits RC of
different combinations a, b c,
d, e, f and g respectivley.
Nyquist and Bode representation of complex
impedance data for ideal electrical circuits
(Nyquist Plot)
The impedance analysis method requires the
determination from the measurements at each frequency f
two parts of the impedance: the real part Z' and the
imaginary part Z". The real
The Arab Journal of Scientific Research
http://aiesa.org/2017/09/the-arab-journal-of-scientific-research/
5
Effect of doxorubicin treatment at the
expression levels of BCL-2 and BAX on MCF7
cell line
Mohammed H. Awwad1, Hayam ELSharawy
1 and Fatma
Ashour1
1Department of Zoology, Faculty of Science, University of
Benha, Benha, Egypt.
Abstract
Breast cancer (BC) is a chemotherapy sensitive tumor.
Doxorubicin hydrochloride (DOX) is one of the most
common chemotherapeutic drugs that used in breast cancer
treatment. It intercalates with DNA and stops the
replication process. And it was found that, following 48h of
DOX treatment, cell death Increases in ER+ breast cancer
cell lines. Here we investigated the effect of DOX treatment
at the antiapoptotic BCL-2 and the proapoptotic BAX genes.
Methods: MCF7 cell line was cultured in the appropriate
media and treated with DOX for 48 hours. Then the
expression levels of BCL-2 and BAX were investigated
using qPCR. Results: the expression of BCL-2 showed a
slight increase in its levels after treatment while BAX gene
showed a striking increase (3.62 fold). Conclusion: our
results was in line with previous studies showed that
treatment with DOX induce apoptosis in MCF7 cells.
Introduction
Breast undergoes a lot of pathological conditions that may
be non-neoplastic (e.g: lesions) or neoplastic (e.g: breast
carcinoma) (Bateman and Shaw 2013). Breast carcinoma
(BC) is one of the most public reasons of cancer death in
women all over the world (Ferlay, Shin et al. 2010). There
are different types of BC; the histological subtypes
including ductal carcinoma and lobular carcinoma. Both
ductal and lobular carcinoma may be either insitu or
invasive (when it invades the surroundings) (Nazário,
Facina et al. 2015). Also the molecular subtypes includes;
ER+ and ER
- according to the status of estrogen receptors
(ER) (Sotiriou, Neo et al. 2003). The response to drugs
differs from ER+ and ER
- (Puhalla, Bhattacharya et al.
2012, Lippman and DICKSON'r 2013). Doxorubicin
hydrochloride (DOX) is one of the most common
chemotherapeutic drugs that used in BC treatment
(Pritchard, Dillon et al. 2012). DOX has been shown to
induce apoptosis (Sharma, Tyagi et al. 2004) and arrest cell
cycle (Rusetskaya, Lukyanova et al. 2009).
BCL-2 is an anti-apoptotic gene which prevent cell
death, Dole and Minn (1995) revealed that high expression
levels of BCL-2 makes the cancer cells resist the apoptotic
effect of chemotherapeutic drugs (Dole, Jasty et al. 1995,
Minn, Rudin et al. 1995). In the other hand BAX is a pro-
apoptotic molecule that stimulate cell death, and its
expression is not affected by estrogen treatment (Teixeira,
Mohammed H. Awwad, Hayam ELSharawy and Fatma Ashour
Vol. 2
6
Reed et al. 1995). We study the effect of DOX treatment on
the expression levels of these two genes in the ER+ MCF7
breast cancer cell line.
Methods
Cell line and Cell growth
Human ER+ breast cancer cell line MCF7
(VACSERA, Cairo, Egypt) was sustained in RPMI high
glucose media (Lonza, Walkersville, MD, USA)
complemented with 1% penicillin/streptomycin (Lonza,
Walkersville, MD, USA), 10% fetal bovine serum (Seralab,
West Sussex, United Kingdom) and 25 µM HEPES (Lonza,
Walkersville, MD, USA). Cells then cultivated in a humid
incubator at 37˚C and 5% CO2.
DOX treatment
After reaching 70-80% confluence, cells then separated into
two groups; Control (C) group: cells grown in fresh media
and drug treated (D) group: cells grown in fresh media
treated with DOX at final concentration of 1µM. Also we
added 17-β estradiol (Sigma Aldrich, St. Louis, MO, USA)
used at final concentration of 10nM to activate estrogen
receptor. Cells were treated for 48h.
RNA Extraction and cDNA Synthesis
RNA was then extracted by means of iTRAZOL reagent
(ITSI Biosciences, Johnstown, PA, USA) by following
steps in its pamphlet. Using Revert aid first strand cDNA
kit (Thermo Fisher scientific, Waltham, MA, USA) we then
synthesed the cDNA also by following steps in its
pamphlet.
4.11. Real time PCR
Using Quantitect SYBR green PCR kit (QIAGEN,
Hilden, Germany), the reactions were prepared and carried
out using Real time PCR machine (MX3005P Stratagene,
San Diego, CA, USA) with the following cycling
conditions: 40 cycles of denaturation at 94˚C, annealing at
temperatures mentioned in table1 depending on the gene
and final extension at 72˚C. Using GAPDH as
housekeeping, we detected changes in gene expression with
relative quantification method (ΔΔCt) with these equations:
Gene expression (amount of target) = 2–ΔΔCt
ΔΔ Ct = Δ Ct sample – Δ Ct calibrator
Δ Ct = Ct tested gene – Ct house keeping
Table 1: primers of genes under study
Gene Forward
primer(5’ to 3’)
Reverseprimer(5
’to 3’)
Melting
temperature
GAPDH
TGATGACATC
AAGAAGGTGG
TGAAG
TCCTTGGAGGC
CATGTGGGCC
AT
52˚c
BAX
GCCCTTTTGCT
TCAGGGTTTC
CTGATCAGTTC
CGGCACCTT 62 ˚c
BCL-2 GAACTGGGGG
AGGATTGTGG
CATCCCAGCCT
CCGTTATCC 56 ˚c
Effect of doxorubicin treatment at the expression levels of BCL-2 and BAX on MCF7 cell line
7
Results
Expression levels of BCL-2, BAX increase in the ER+
MCF7 cells after DOX treatment.
We found that DOX treatment increased the expression
levels of BCL-2 and BAX after 48h of treatment. BCL-2
showed 1.71 fold change in its expression after 48h of DOX
treatment. Similarly BAX showed 3.63 fold change in its
expression after 48h of treatment (figure 1).
Figure 1: Gene expression of BCL-2 and BAX in MCF7
cells after 48h DOX treatment. Cells were incubated with
1µM DOX for 48 h. Changes in gene expression of BCL-2
and BAX after treatment were detected. They showed
increase in their expression after 48h of treatment.
Discussion
Doxorubicin hydrochloride is one of the most
commonly used chemotherapeutic agents in BC
management(Pritchard, Dillon et al. 2012). In BC cell lines
a dose of ≥ 1µM of DOX decreases cell viability, promotes
apoptosis and stops the cell cycle(Sharma, Tyagi et al.
2004, Lüpertz, Wätjen et al. 2010). Here we tested the
effect of DOX treatment on ER+
MCF7 cell lines and how it
alters the mRNA BCL-2 and BAX.
When the cells were exposed to the drug for 48h,
we have found that the expression of BCL-2 in was
increased. But this contrast with other studies revealed that
DOX down regulates BCL-2 mRNA levels (Mcgahon,
Costa Pereira et al. 1998, Leung and Wang 1999). The
difference between our finding and these studies could be
because those studies revealed the action of DOX alone but
in our study we treated the cells with estrogen to activate
estrogen receptors. Indeed estrogen was shown to reverse
the action of DOX alone and increase BCL-2 levels
(Teixeira, Reed et al. 1995). And this agrees with Lacroix
and Leclercq (2004) who showed that active ERα prevents
apoptosis of breast cancer cells via increasing the
expression levels of BCL-2(Lacroix and Leclercq 2004).
We also found that the expression of BAX
increased tremendously after treatment with DOX. Our
BAX data is in line with other studies showed that BAX is a
pro-apoptotic molecule motivates cell death and is
overexpressed in MCF7 cells after treatment with
DOX(Leung and Wang 1999, Sharifi, Barar et al. 2015) and
0
0.5
1
1.5
2
2.5
3
3.5
4
BCL-2
fold change in BCL-2 & BAX compared with untreated control
fold change
Mohammed H. Awwad, Hayam ELSharawy and Fatma Ashour
Vol. 2
8
its expression is not affected by estrogen
treatment(Teixeira, Reed et al. 1995).
It was found that, following 48h of DOX
treatment, cell death Increases in ER+ breast cancer cell
lines (Sharma, Tyagi et al. 2004) and although we showed
that the mRNA expression levels of BCL-2 and BAX are
increased in ER+ MCF7 cells, it is not clear whether this
change may lead to apoptosis or not. More studies
investigating the gene expression profiles and apoptotic and
viability assays of MCF7 are recommended to identify the
final fate of the cells after DOX treatment.
Effect of doxorubicin treatment at the expression levels of BCL-2 and BAX on MCF7 cell line
9
References
Bateman, A. C. and E. C. Shaw (2013). "Breast pathology."
Surgery (Oxford) 31(1): 4-10.
Dole, M. G., R. Jasty, M. J. Cooper, C. B. Thompson, G.
Nuñez and V. P. Castle (1995). "Bcl-xL is expressed in
neuroblastoma cells and modulates chemotherapy-induced
apoptosis." Cancer research 55(12): 2576-2582.
Ferlay, J., H. R. Shin, F. Bray, D. Forman, C. Mathers and
D. M. Parkin (2010). "Estimates of worldwide burden of
cancer in 2008: GLOBOCAN 2008." International journal
of cancer 127(12): 2893-2917.
Lacroix, M .and G. Leclercq (2004). "Relevance of breast
cancer cell lines as models for breast tumours: an update."
Breast cancer research and treatment 83(3): 249-289.
Leung, L. K. and T. T. Wang (1999). "Differential effects
of chemotherapeutic agents on the Bcl ‐2/ Bax apoptosis
pathway in human breast cancer cell line MCF‐7." Breast
cancer research and treatment 55(1): 73-83.
Lippman, M. E. and R. B. DICKSON'r (2013). Mechanisms
of growth control in normal and malignant breast
epithelium. Recent Progress in Hormone Research:
Proceedings of the 1988 Laurentian Hormone Conference,
Academic Press.
Lüpertz, R., W. Wätjen, R. Kahl and Y. Chovolou (2010).
"Dose-and time-dependent effects of doxorubicin on
cytotoxicity, cell cycle and apoptotic cell death in human
colon cancer cells." Toxicology 271(3): 115-121.
Mcgahon, A. J., A. P. Costa Pereira, L. Daly and T. G.
Cotter (1998). "Chemotherapeutic drug‐induced apoptosis
in human leukaemic cells is independent of the Fas
(APO‐1/CD95) receptor/ligand system." British journal of
haematology 101(3): 539-547
.
Minn, A. J., C. M. Rudin, L. H. Boise and C. B. Thompson
(1995). "Expression of bcl-xL can confer a multidrug
resistance phenotype." Blood 86(5): 1903-1910.
Nazário, A. C. P., G. Facina and J. R. Filassi (2015).
"Breast cancer: news in diagnosis and treatment." Revista
da Associação Médica Brasileira 61(6): 543-552.
Pritchard, J. E., P. M. Dillon, M. R. Conaway, C. M. Silva
and S. J. Parsons (2012). "A mechanistic study of the effect
of doxorubicin/adriamycin on the estrogen response in a
breast cancer model." Oncology 83(6): 305-320.
Puhalla, S., S. Bhattacharya and N. E. Davidson (2012).
"Hormonal therapy in breast cancer: a model disease for the
personalization of cancer care." Molecular oncology 6(2):
222-236.
Rusetskaya, N., N. Y. Lukyanova and V. Chekhun (2009).
"Molecular profile and cell cycle in MCF-7 and MCF-
7/Dox cells exposed to conventional and liposomal forms of
doxorubicin." Exp Oncol 31: 140-143.
Sharifi, S., J. Barar, M. S. Hejazi and N. Samadi (2015 .)
"Doxorubicin changes Bax/Bcl-xL ratio, caspase-8 and 9 in
breast cancer cells." Advanced pharmaceutical bulletin
5(3): 351.
Sharma, G., A. K. Tyagi, R. P. Singh, D. C. Chan and R.
Agarwal (2004). "Synergistic anti-cancer effects of grape
seed extract and conventional cytotoxic agent doxorubicin
against human breast carcinoma cells." Breast cancer
research and treatment 85(1): 1-12.
Sotiriou, C., S.-Y. Neo, L. M. McShane, E. L. Korn, P. M.
Long, A. Jazaeri, P. Martiat, S. B. Fox, A. L. Harris and E.
T. Liu (2003). "Breast cancer classification and prognosis
based on gene expression profiles from a population-based
study." Proceedings of the National Academy of Sciences
100(18): 10393-10398.
Teixeira, C., J. C. Reed and M. C. Pratt (1995). "Estrogen
promotes chemotherapeutic drug resistance by a mechanism
involving Bcl-2 proto-oncogene expression in human breast
cancer cells." Cancer research 55(17): 3902-3907.