Determination of Ultra Trace Levels of Copper in Whole Blood by Adsorptive Stripping Voltammetry

Attar, Tarik,Harek, Yahia,Larabi, Lahcen Korean Chemical Society 2013 대한화학회지 Vol.57 No.5

A selective and sensitive method for simultaneous determination of copper in blood by adsorptive differential pulse cathodic stripping voltammetry is presented. The procedure involves an adsorptive accumulation of Cu(II)-ETSC (4- ethyl-3-thiosemicarbazide) on a hanging mercury drop electrode, followed by a stripping voltammetry measurement of reduction current of adsorbed complex at about -715 mV. The optimum conditions for the analysis of copper (II) ion are : pH 10.3, concentration of 4-ethyl-3-thiosemicarbazide $3.25{\times}10^{-6}$ M and an accumulation potential of -100 mV. The peak current is proportional to the concentration of copper over the range 0.003-125 ng/mL with a detection limit of 0.001 ng/mL and an accumulation time of 60 s. Moreover, with the use of the proposed method, there is a considerable improvement in the detection limit, the linear dynamic range and the deposition time, compared with the methods of adsorptive stripping voltammetry for the determination of copper. The developed method was validated by analysis of whole blood certified reference materials.

Interleukin-6-174 Promoter Polymorphism and Susceptibility to Hepatitis B Virus Infection as a Risk Factor for Hepatocellular Carcinoma in Iran

Attar, Marzieh,Azar, Saleh Shahbazi,Shahbazi, Majid Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.5

Background: Hepatitis B virus (HBV) is a major risk factor for hepatocellular carcinoma (HCC). Cytokines play an important role in the regulation of immune responses and defense against viral infections. Human interleukin 6 (IL6) is a multifunctional cytokine that participates in these processes. Objective: The aim of this study was to assess the IL6-174 gene polymorphism in patients with chronic hepatitis B virus (HBV) infection as compared with healthy controls in an Iranian population. Materials and Methods: Totals of 297 HBV patients and 368 control individuals were evaluated. Genomic DNA was extracted from peripheral blood and the SSP-PCR (sequence specific primer-polymerase chain reaction) method was applied for genotyping. Results: The frequencies of genotypes C/C, G/G and C/G in HBV cases were 4.7%, 34.3%, 60.9% and in controls were 12.8%, 39.7% and 47.6%, respectively. The frequencies of G and C allele in patients and controls were 78.1%, 21.9% and 67.4%, 32.6 % respectively. There was a significant difference in the frequencies of G/G genotype (CI=1.8-7.1, OR=3.47, P=0.00001) and G allele (CI=1.34-2.23, OR=1.72, P=0.0001) between HBV patients and the control group. Conclusions: These findings suggest that the IL6-174 C/G genotype and the G allele are strongly associated with susceptibility to HBV infection. Demographic information showed that most of the subjects were male (74.4%). According to high frequency of G/G genotype in male participants (63.1%) men probably are more susceptible to hepatitis than women.

Ovarian Cancer: Interplay of Vitamin D Signaling and miRNA Action

Attar, Rukset,Gasparri, Maria Luisa,Di Donato, Violante,Yaylim, Ilhan,Halim, Talha Abdul,Zaman, Farrukh,Farooqi, Ammad Ahmad Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.8

Increasing attention is being devoted to the mechanisms by which cells receive signals and then translate these into decisions for growth, death, or migration. Recent findings have presented significant breakthroughs in developing a deeper understanding of the activation or repression of target genes and proteins in response to various stimuli and of how they are assembled during signal transduction in cancer cells. Detailed mechanistic insights have unveiled new maps of linear and integrated signal transduction cascades, but the multifaceted nature of the pathways remains unclear. Although new layers of information are being added regarding mechanisms underlying ovarian cancer and how polymorphisms in VDR gene influence its development, the findings of this research must be sequentially collected and re-interpreted. We divide this multi-component review into different segments: how vitamin D modulates molecular network in ovarian cancer cells, how ovarian cancer is controlled by tumor suppressors and oncogenic miRNAs and finally how vitamin D signaling regulates miRNA expression. Intra/inter-population variability is insufficiently studied and a better understanding of genetics of population will be helpful in getting a step closer to personalized medicine.

TRAIL Based Therapy: Overview of Mesenchymal Stem Cell Based Delivery and miRNA Controlled Expression of TRAIL

Attar, Rukset,Sajjad, Farhana,Qureshi, Muhammad Zahid,Tahir, Fizza,Hussain, Ejaz,Fayyaz, Sundas,Farooqi, Ammad Ahmad Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.16

Rapidly increasing number of outstanding developments in the field of TRAIL mediated signaling have revolutionized our current information about inducing and maximizing TRAIL mediated apoptosis in resistant cancer cells. Data obtained with high-throughput technologies have provided finer resolution of tumor biology and now it is known that a complex structure containing malignant cells strictly coupled with a large variety of surrounding cells constitutes the tumor stroma. Utility of mesenchymal stem cells (MSCs) as cellular vehicles has added new layers of information. There is sufficient experimental evidence substantiating efficient gene deliveries into MSCs by retroviral, lentiviral and adenoviral vectors. Moreover, there is a paradigm shift in molecular oncology and recent high impact research has shown controlled expression of TRAIL in cancer cells on insertion of complementary sequences for frequently downregulated miRNAs. In this review we have attempted to provide an overview of utility of TRAIL engineered MSCs for effective killing of tumor and potential of using miRNA response elements as rheostat like switch to control expression of TRAIL in cancer cells.

Optimized precipitation process for efficient and size-controlled synthesis of hydroxyapatite–chitosan nanocomposite

Attar Nosrati Sima,Alizadeh Robabeh,Ahmadi Seyed Javad,Erfani Mostafa 한국세라믹학회 2020 한국세라믹학회지 Vol.57 No.6

It is known that the physicochemical characteristics of nanocomposites strongly aff ected by synthesis route and conditions. In this study, hydroxyapatite–chitosan nanocomposite as a substance with extensive medical application has been prepared by precipitation method under controlled conditions. To evaluation of the main synthesis parameters, including mixing ratio of precursors, pH and drying condition and investigation of their eff ect on the fi nal products characteristics, a statistical design of experiments approach via Minitab 18 has been applied. For this purpose 12 sets of experimental run have been designed and performed based on various combinations of aforementioned parameters and the characteristics of the prepared samples have been elucidated by means of Fourier transformed infrared spectroscopy, X-ray diff raction, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy and the particle size analysis. The results represent the potential impact of synthesis parameters, their interaction with each other and estimation of optimum synthesis conditions. It is revealed that mean particle size of HA-CS nanocomposite reduced by increasing the content of hydroxyapatite and increment of reaction pH to values higher than 10. Also it is founded that freeze drying process, can be used as a superior drying method for the preparation of HA-CS nanocomposite with uniform particle size.

Absence of Correlation between Changes in the Number of Endothelial Progenitor Cell Subsets

Armin Attar,Kamran Aghasadeghi,Mohammad Ebrahim Parsanezhad,Bahia Namavar Jahromi,Mojtaba Habibagahi 대한심장학회 2015 Korean Circulation Journal Vol.45 No.4

Background and Objectives: Previously, various methodologies were used to enumerate the endothelial progenitor cells (EPCs). We now know that these methodologies enumerate at least three different EPC subsets: circulating angiogenic cells (CACs), colony-forming unit endothelial cells (CFU-ECs), and endothelial colony-forming cells (ECFCs). It is not clear whether there is a correlation between changes in the number of these subsets. The aim of the current study is to find an answer to this question. Materials and Methods: The number of all EPC subsets was quantified in the peripheral blood of nine pregnant women in their first and third trimesters of pregnancy. We enumerated 14 cell populations by quantitative flow-cytometry using various combinations of the markers, CD34, CD133, CD309, and CD45, to cover most of the reported phenotypes of CACs and ECFCs. Culturing technique was used to enumerate the CFU-ECs. Changes in the number of cells were calculated by subtracting the number of cells in the first trimester peripheral blood from the number of cells in the third trimester peripheral blood, and correlations between these changes were analyzed. Results: The number of CFU-ECs did not correlate with the number of ECFCs and CACs. Also, CACs and ECFCs showed independent behaviors. However, the number of CACs showed a strong correlation with the number of CD133+CD309+ cells (p=0.001) and a moderate correlation with the number of CD34+CD309+ cells (p=0.042). Also, the number of ECFCs was correlated with the number of CD309+CD45- cells (p=0.029) and CD34+CD45- cells (p=0.03). Conclusion: Our study showed that the three commonly used methods for quantifying EPC subsets represent different cells with independent behaviors. Also, any study that measured the number of EPCs using the flow cytometry method with a marker combination that lacks CD309 may be inaccurate.

The effect of Al2O3 nano additions on failure of GFRP plate with two parallel pin loaded holes

Mohammadmahdi Attar,S. Mahdi Ahmadpour,S. Shahin Banisadr,Arash Mohammadi,S. Zahra Mirmoradi,Zohreh Shirazi 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.6

The aim of this study is to scrutinize the effect of nano-additions on failure modes and loads of glass-epoxy laminate subjected two parallel pin-loaded holes, experimentally and numerically. Furthermore, the effect of physical and geometrical parameters such as the ratio of free edge distance of laminated composite to holes diameter (e/d) and the ratio of centre to centre distances of holes to holes diameter (M/d) have been investigated. Afterwards, to exactly prognosticate failure modes and the ultimate load obtained from the experimental procedure, a numerical simulation in finite element software was implemented. There have found a close agreement between two methods. It should be acknowledged that after augmenting glass-epoxy laminate with nano-addition Al 2 O 3 , there was seen to be a clear difference between the two samples while the bearing strength of reinforced samples has been improved.

Mechanical behavior of a cylindrical capacitive micro - switch compared to a straight beam type

Ashkan Attar,Mohammad Fathalilou,Ghader Rezazadeh 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.5

This paper introduces a novel cylindrical capacitive micro-switch which has different pull-in voltage, frequency response and contact area compared to the conventional straight beam switch. After presenting a mathematical model, governing equation of motion of the cylindrical switch has been solved by Galerkin-based reduced order models. The results have shown that the presented model has lower pull-in voltage than straight beam with the same dimensions. Also, the novel model exhibits considerable difference in frequency response in comparison with the other model. By applying the HERTZ relations for the contact area, a mathematical rough estimation for the contact area in switching state has done. The estimated results reveal that the contact area in cylindrical switch is about 56 % of the straight switch with the same dimensions.

The use of SMA wire dampers to enhance the seismic performance of two historical Islamic minarets

El-Attar, Adel,Saleh, Ahmed,El-Habbal, Islam,Zaghw, Abdel Hamid,Osman, Ashraf Techno-Press 2008 Smart Structures and Systems, An International Jou Vol.4 No.2

This paper represents the final results of a research program sponsored by the European Commission through project WIND-CHIME ($\underline{W}$ide Range Non-$\underline{IN}$trusive $\underline{D}$evices toward $\underline{C}$onservation of $\underline{HI}$storical Monuments in the $\underline{ME}$diterranean Area), in which the possibility of using advanced seismic protection technologies to preserve historical monuments in the Mediterranean area is investigated. In the current research, the dynamic characteristics of two outstanding Mamluk-Style minarets, which similar minarets were reported to experience extensive damage during Dahshur 1992 earthquake, are investigated. The first minaret is the Qusun minaret (1337 A.D, 736 Hijri Date (H.D)) located in El-Suyuti cemetery on the southern side of the Salah El-Din citadel. The minaret is currently separated from the surrounding building and is directly resting on the ground (no vaults underneath). The total height of the minaret is 40.28 meters with a base rectangular shaft of about 5.42 ${\times}$ 5.20 m. The second minaret is the southern minaret of Al-Sultaniya (1340 A.D, 739 H.D). It is located about 30.0 meters from Qusun minaret, and it is now standing alone but it seems that it used to be attached to a huge unidentified structure. The style of the minaret and its size attribute it to the first half of the fourteenth century. The minaret total height is 36.69 meters and has a 4.48 ${\times}$ 4.48 m rectangular base. Field investigations were conducted to obtain: (a) geometrical description of the minarets, (b) material properties of the minarets' stones, and (c) soil conditions at the minarets' location. Ambient vibration tests were performed to determine the modal parameters of the minarets such as natural frequencies and mode shapes. A $1/16^{th}$ scale model of Qusun minaret was constructed at Cairo University Concrete Research Laboratory and tested under free vibration with and without SMA wire dampers. The contribution of SMA wire dampers to the structural damping coefficient was evaluated under different vertical loads and vibration amplitudes. Experimental results were used along with the field investigation data to develop a realistic 3-D finite element model that can be used for seismic risk evaluation of the minarets. Examining the updated finite element models under different seismic excitations indicated the vulnerability of such structures to earthquakes with medium to high a/v ratio. The use of SMA wire dampers was found feasible for reducing the seismic risk for this type of structures.

Memory response in elasto-thermoelectric spherical cavity

El-Attar, Sayed I.,Hendy, Mohamed H.,Ezzat, Magdy A. Techno-Press 2020 Coupled systems mechanics Vol.9 No.4

A mathematical model of electro-thermoelasticity subjected to memory-dependent derivative (MDD) heat conduction law is applied to a one-dimensional problem of a thermoelectric spherical cavity exposed to a warm stun that is an element of time in the presence of a uniform magnetic field. Utilizing Laplace transform as an instrument, the issue has been fathomed logically within the changed space. Numerical inversion of the Laplace transform is carried for the considered distributions and represented graphically. Some comparisons are shown in the figures to estimate the effects of MDD parameters and thermoelectric properties on the behavior of all considered fields.