Negative HER2/neu Amplification Using Immunohistochemistry and Chromogenic in Situ Hybridization Techniques in Skin Melanoma Cases

Shayanfar, Nasrin,Bahari, Leila,Safaie-Naraghi, Zahra,Kamyab, Kambiz,Gheytanchi, Elmira,Rezaei, Nima Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.2

Background: This study was performed to evaluate the amplification of HER-2/neu in patients with melanoma. Materials and Methods: Amplification of HER-2/neu was evaluated in a group of patients with melanoma, referred to two referral centers in Tehran, using immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH) techniques. Results: Forty patients with mean age $57.9{\pm}19.5years$ were enrolled in this study. The most frequent type of melanoma was acral, while lower limbs were the most frequent sites. The amplification of HER2/neu was negative in 97.5% of patients with IHC and in 100% of patients with CISH technique. Only one case (2.5%) shows weak positive staining (+2) in IHC method. Fifty five percent of melanoma was ulcerative, and the most common stages of tumors were stages 4b and 3b. More than 47% of cases were in Clark level III, while the mean of Breslow thickness was $3.56{\pm}2.87mm$. The stage of the case that showed weakly positive staining (2+) in IHC was 4b. Conclusions: The amplification of HER2/neu biomarker was negative in patients with melanoma, using both CISH and IHC techniques.

The effects of consolidation time on the strength and failure behavior of freshwater ice rubble

Shayanfar, Hamid,Bailey, Eleanor,Pritchett, Robert,Taylor, Rocky The Society of Naval Architects of Korea 2018 International Journal of Naval Architecture and Oc Vol.10 No.3

Medium-scale tests were conducted to measure and observe the strength and failure behavior of freshwater ice rubble. A custom box measuring $3.05m{\times}0.94m{\times}0.94m$, with Plexiglas walls was built so that failure mechanisms could be observed. Ice rubble beams of nominal thickness 50 cm were produced by placing randomly sized ice pieces into the box filled with water at its freezing temperature. After the specified consolidation time, ranging between 0.2 and 70.5 h, the ice rubble beam was deformed by pushing a platen vertically downwards though the center of the beam until failure. For consolidation times less than 4 h, the ice beam failed progressively and tended to fail by shearing on macroscopic scale. At times greater than 4 h the beam failed by bending. The change in failure behaviour has been attributed to the degree of bonding between ice blocks.

Optimization of modal load pattern for pushover analysis of building structures

Shayanfar, Mohsen Ali,Ashoory, Mansoor,Bakhshpoori, Taha,Farhadi, Basir Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.1

Nonlinear Static Procedures (NSPs) have been developed as a practical tool to estimate the seismic demand of structures. Several researches have accomplished to minimize errors of NSPs, namely pushover procedures, in the Nonlinear Time History Analysis (NTHA), as the most exact method. The most important issue in a typical pushover procedure is the pattern and technique of loading which are extracted based on structural dynamic fundamentals. In this paper, the coefficients of modal force combination is focused involving a meta-heuristic optimization algorithm to find the optimum load pattern which results in a response with minimum amount of errors in comparison to the NTHA counterpart. Other parameters of the problem are based on the FEMA recommendations for pushover analysis of building structures. The proposed approach is implemented on a high-rise 20 storey concrete moment resisting frame under three earthquake records. In order to demonstrate the effectiveness and robustness of the studied procedure the results are presented beside other well-known pushover methods such as MPA and the FEMA procedures, and the results show the efficiency of the proposed load patterns.

The effects of consolidation time on the strength and failure behavior of freshwater ice rubble

Hamid Shayanfar,Eleanor Bailey,Robert Pritchett,Rocky Taylor 대한조선학회 2018 International Journal of Naval Architecture and Oc Vol.10 No.3

Medium-scale tests were conducted to measure and observe the strength and failure behavior of freshwater ice rubble. A custom box measuring 3.05m 0.94m 0.94 m, with Plexiglas walls was built so that failure mechanisms could be observed. Ice rubble beams of nominal thickness 50 cm were produced by placing randomly sized ice pieces into the box filled with water at its freezing temperature. After the specified consolidation time, ranging between 0.2 and 70.5 h, the ice rubble beam was deformed by pushing a platen vertically downwards though the center of the beam until failure. For consolidation times less than 4 h, the ice beam failed progressively and tended to fail by shearing on macroscopic scale. At times greater than 4 h the beam failed by bending. The change in failure behaviour has been attributed to the degree of bonding between ice blocks.

Analysis-oriented model for seismic assessment of RC jacket retrofitted columns

Javad Shayanfar,Meysam Omidalizadeh,Mahdi Nematzadeh 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.37 No.3

One of the most common strategies for retrofitting as-built reinforced concrete (RC) columns is to enlarge the existing section through the application of a new concrete layer reinforced by both steel transverse and longitudinal reinforcements. The present study was dedicated to developing a comprehensive model to predict the seismic behavior of as-built RC jacketed columns. For this purpose, a new sectional model was developed to perform moment-curvature analysis coupled by the plastic hinge method. In this analysis-oriented model, new methodologies were suggested to address the impacts of axial, flexural and shear mechanisms, variable confining pressure, eccentric loading, longitudinal bar buckling, and varying axial load. To consider the effective interaction between core and jacket, the monolithic factor approach was adopted to extent the response of the monolithic columns to that of a respective RC jacket strengthened column. Next, parametric studies were implemented to examine the effectiveness of the main parameters of the RC jacket strategy in retrofitting as-built RC columns. Ultimately, the reliability of the developed analytical model was validated against a series of experimental results of as-built and retrofitted RC columns.

Numerical model to simulate shear behaviour of RC joints and columns

J.Shayanfar,H. Akbarzadeh Bengar 사단법인 한국계산역학회 2016 Computers and Concrete, An International Journal Vol.18 No.4

In this paper, a new numerical model for the evaluation of the seismic behaviour of existing reinforced concrete (RC) structure with considering the effect of variation of applied axial load on columns is presented. Focus is given on developing accurate and practical models for simulating nonlinearities in joint core as well as column under varying axial load. For exterior as well as interior joints, according to experimental and finite element results, principal tensile stresses versus shear deformation relations in joint core are recommended. Moreover, to consider the effects of stirrup on the principal tensile stress-shear deformation relation, an incremental procedure is proposed based on the Mohr theory. According to the proposed numerical model, complex nonlinear behaviour of joint core is simulated by two diagonal axial springs so that the effect of variation of axial load is also considered. The properties of these springs are determined based on the proposed principal tensile stress-shear deformation relation in the joint core. Moreover, the shear and flexural nonlinear behaviour of RC beams and columns is also simulated by rotational springs. A simplified methodology is developed to consider the effects of axial load variation on shear and flexural nonlinear behaviour of RC columns. To demonstrate the capability of the proposed numerical model at structural level, two RC frames with various failure modes are investigated. The results confirm the ability of the model in predicting the nonlinear behaviour of the frame, which can provide an alternative method for engineers in practice.

A practical model for simulating nonlinear behaviour of FRP strengthened RC beam-column joints

Javad Shayanfar,Habib Akbarzadeh Bengar 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.27 No.1

Generally, beam-column joints are taken into account as rigid in assessment of seismic performance of reinforced concrete (RC) structures. Experimental and numerical studies have proved that ignoring nonlinearities in the joint core might crucially affect seismic performance of RC structures. On the other hand, to improve seismic behaviour of such structures, several strengthening techniques of beam–column joints have been studied and adopted in practical applications. Among these strengthening techniques, the application of FRP materials has extensively increased, especially in case of exterior RC beam-column joints. In current paper, to simulate the inelastic response in the core of RC beam–column joints strengthened by FRP sheets, a practical joint model has been proposed so that the effect of FRP sheets on characteristics of an RC joint were considered in principal tensile stress-joint rotation relations. To determine these relations, a combination of experimental results and a mechanically-based model has been developed. To verify the proposed model, it was applied to experimental specimens available in the literature. Results revealed that the model could predict inelastic response of as-built and FRP strengthened joints with reasonable precision. The simple analytic procedure and the use of experimentally computed parameters would make the model sufficiently suitable for practical applications.

Optimization of modal load pattern for pushover analysis of building structures

Mohsen Ali Shayanfar,Mansoor Ashoory,Taha Bakhshpoori,Basir Farhadi 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.1

Nonlinear Static Procedures (NSPs) have been developed as a practical tool to estimate the seismic demand of structures. Several researches have accomplished to minimize errors of NSPs, namely pushover procedures, in the Nonlinear Time History Analysis (NTHA), as the most exact method. The most important issue in a typical pushover procedure is the pattern and technique of loading which are extracted based on structural dynamic fundamentals. In this paper, the coefficients of modal force combination is focused involving a meta-heuristic optimization algorithm to find the optimum load pattern which results in a response with minimum amount of errors in comparison to the NTHA counterpart. Other parameters of the problem are based on the FEMA recommendations for pushover analysis of building structures. The proposed approach is implemented on a high-rise 20 storey concrete moment resisting frame under three earthquake records. In order to demonstrate the effectiveness and robustness of the studied procedure the results are presented beside other well-known pushover methods such as MPA and the FEMA procedures, and the results show the efficiency of the proposed load patterns.

Corrosion effects on tension stiffening behavior of reinforced concrete

M. A. Shayanfar,M. Ghalehnovi,A. Safiey 한국계산역학회 2007 Computers and Concrete, An International Journal Vol.4 No.5

The investigation of corrosion effects on the tensile behavior of reinforced concrete (RC) members is very important in region prone to high corrosion conditions. In this article, an experimental study concerning corrosion effects on tensile behavior of RC members is presented. For this purpose, a comprehensive experimental program including 58 cylindrical reinforced concrete specimens under various levels of corrosion is conducted. Some of the specimens (44) are located in large tub containing water and salt (5% salt solution); an electrical supplier has been utilized for the accelerated corrosion program. Afterwards, the tensile behavior of the specimens was studied by means of the direct tension tests. For each specimen, the tension stiffening curve is plotted, and their behavior at various load levels is investigated. Average crack spacing, loss of cross-section area due to corrosion, the concrete contribution to the tensile response for different strain levels, and maximum bond stress developed at each corrosion level are studied, and their appropriate relationships are proposed. The main parameters considered in this investigation are: degree of corrosion (Cw), reinforcement diameter (d), reinforcement ratio (?), clear concrete cover (c), ratio of clear concrete cover to rebar diameter (c/d), and ratio of rebar diameter to reinforcement percentage (d/?).

Experimental study of cyclic behavior of composite vertical shear link in eccentrically braced frames

M.A. Shayanfar,M.A. Barkhordari,A.R. Rezaeian 국제구조공학회 2012 Steel and Composite Structures, An International J Vol.12 No.1

This paper is an experimental study on the behavior of vertical shear link in normal (steel section with and without stiffener) and composite (steel section with concrete located at the area limited to web and flanges of the section) configurations. This study is mainly aimed to perceive failure mechanism, collect laboratory data, and consider the effect of number of transverse reinforcements on strength and ductility of composite vertical links. There have been four specimens selected for examining the effects of different details .The first specimen was an I section with no stiffener, the second composed of I section with stiffeners provided according to AISC 2005. The third and fourth specimens were composed of I sections with reinforced concrete located at the area between its flanges and web. The tests carried out were of quasi-static type and conducted on full scale specimens. Experimental findings show remarkable increase in shear capacity and ductility of the composite links as compared to the normal specimens.