Nucleotide Sequence, Structural Investigation and Homology Modeling Studies of a Ca²⁺-independent α-amylase with Acidic pH-profile

Sajedi, Reza Hassan,Taghdir, Majid,Naderi-Manesh, Hossein,Khajeh, Khosro,Ranjbar, Bijan Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.3

The novel $\alpha$-amylase purified from locally isolated strain, Bacillus sp. KR-8104, (KRA) (Enzyme Microb Technol; 2005; 36: 666-671) is active in a wide range of pH. The enzyme maximum activity is at pH 4.0 and it retains 90% of activity at pH 3.5. The irreversible thermoinactivation patterns of KRA and the enzyme activity are not changed in the presence and absence of $Ca^{2+}$ and EDTA. Therefore, KRA acts as a $Ca^{2+}$-independent enzyme. Based on circular dichroism (CD) data from thermal unfolding of the enzyme recorded at 222 nm, addition of $Ca^{2+}$ and EDTA similar to its irreversible thermoinactivation, does not influence the thermal denaturation of the enzyme and its Tm. The amino acid sequence of KRA was obtained from the nucleotide sequencing of PCR products of encoding gene. The deduced amino acid sequence of the enzyme revealed a very high sequence homology to Bacillus amyloliquefaciens (BAA) (85% identity, 90% similarity) and Bacillus licheniformis $\alpha$-amylases (BLA) (81% identity, 88% similarity). To elucidate and understand these characteristics of the $\alpha$-amylase, a model of 3D structure of KRA was constructed using the crystal structure of the mutant of BLA as the platform and refined with a molecular dynamics (MD) simulation program. Interestingly enough, there is only one amino acid substitution for KRA in comparison with BLA and BAA in the region involved in the calcium-binding sites. On the other hand, there are many amino acid differences between BLA and KRA at the interface of A and B domains and around the metal triad and active site area. These alterations could have a role in stabilizing the native structure of the loop in the active site cleft and maintenance and stabilization of the putative metal triad-binding site. The amino acid differences at the active site cleft and around the catalytic residues might affect their pKa values and consequently shift its pH profile. In addition, the intrinsic fluorescence intensity of the enzyme at 350 nm does not show considerable change at pH 3.5-7.0.

Behavior study of NC and HSC RCCs confined by GRP casing and CFRP wrapping

Fathollah Sajedi,Mahdi Shariati 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.30 No.5

This paper presents the results of axial compression testing and numerical modeling on reinforced concrete columns (RCC) with normal concrete (NC) and high-strength concrete (HSC), RCC confined by glass-fiber reinforced plastic pipes (GRP) casing as well as carbon fiber reinforced polymer (CFRP), The major parameters evaluated in the experiments were the effects of concrete type, GRP casing and CFRP wrapping, as well as the number of CFRP layers. 12 cylindrical RCC (150×600 mm) were prepared and divided into two groups, NC and HSC. Each group was divided into two parts; with and without GRP casing. In each part, one column was without CFRP strengthening layer, a column was wrapped with one CFRP layer and another column with two CFRP layers. All columns were tested under concentrated compression load. Numerical modeling was performed using ABAQUS software and the results of which were compared with experimental findings. A good agreement was found between the results. Results indicated that the utilization of CFRP wrapping and GRP casing improved compression capacity and ductility of RCC. The addition of one and two layer-FRP wrapping increased capacity in the NC group to an average of 18.5% and 26.5% and in the HSC group to an average of 10.2% and 24.8%. Meanwhile, the utilization of GRP casing increased the capacity of the columns by 3 times in the NC group and 2.38 times in the HSC group. The results indicated that although both CFRP wrapping and GRP casing increased confinement, the GRP casing gave more increase capacity and ductility of the RCC due to higher confinement. Furthermore, the confinement effect was higher on NC group.

Order υ Entropy and Cross Entropy of Uncertain Variables for Portfolio Selection

Alireza Sajedi,Gholamhossein Yari 한국지능시스템학회 2020 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.20 No.1

In this study, we proposed definition of order υ entropy and order υ cross entropy of uncertain variables under uncertainty theory. Moreover, order υ entropy and order υ cross entropy of uncertain variables were applied to mean-variance portfolio selection model. We also attempted to examine the applications of these measures with different order υ values. The effect of the υ in order υ entropy and cross entropy on portfolio selection were considered using the order υ entropy-mean-variance and 571781799order υ entropy-mean-variance presented models. As a result of this approach, by using different values of υ, diversity of asset allocations could be achieved.

Nucleotide Sequence, Structural Investigation and Homology Modeling Studies of a Ca2+-independent α-amylase with Acidic pH-profile

( Reza Hassan Sajedi ),( Majid Taghdir ),( Hossein Naderi Manesh ),( Khosro Khajeh ),( Bijan Ranjbar ) 생화학분자생물학회 2007 BMB Reports Vol.40 No.3

Investigating the effect of using three pozzolans separately and in combination on the properties of self-compacting concrete

Orak, Milad,Sajedi, Fathollah Techno-Press 2021 Advances in nano research Vol.11 No.2

Today, the tendency to use self-compacting concrete (SCC) is expanding because of its significant benefits. In this study, SCC was made by using native materials and then different pozzolans were replaced instead of a part of cement and the rheological and mechanical properties and microstructure of the concrete were investigated. The pozzolans containing of metakaolin (15%, 25% and 35%), silica fume (6%, 12% and 18%) and fly ash (20%, 35% and 50%) were replaced instead of a part of cement separately or simultaneously. Self-compaction tests including slump flow, T500, L-box, U-box, and J-ring as well as mechanical tests including compressive strength, splitting tensile strength, and static modulus of elasticity were performed on the specimens. The results showed that the pozzolans improved the microstructure of the SCC and the secondary reactions improved the mechanical properties of the concrete containing the pozzolans at older ages than the reference concrete. At 15% replacement, metakaolin increased the 180-day compressive strength up to 106 MPa that was about 18% more than reference concrete. In ternary mixtures the maximum and minimum rate were 29% and 19%, respectively, and in quaternary mixtures the rates were significant and increased up to 46%, while the rate for reference concrete was 20%. This significant growth was probably due to the secondary reaction of pozzolans with calcium hydroxide residue from cement hydration.

Portfolio Selection in the Credibilistic Framework Using Renyi Entropy and Renyi Cross Entropy

Yari, Gholanhossein,Sajedi, Alireza,Rahimi, Mohamadtaghi Korean Institute of Intelligent Systems 2018 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.18 No.1

In this study, the Renyi entropy-mean-variance maximization and Renyi cross entropy-mean-variance minimization models for portfolio selection with fuzzy return were investigated under the credibility theory framework. We also attempted to examine the relationship between credibilistic Renyi entropy-mean-variance and Renyi cross entropy-mean-variance models. The effect of the ${\upsilon}$ parameter in Renyi entropy and Renyi cross entropy on optimal portfolio selection was considered using the presented models.

Three-dimensional analysis of the distal movement of maxillary 1st molars in patients fitted with mini-implant-aided trans-palatal arches

Amirfarhang Miresmaeili,Ahmad Sajedi,Abbas Moghimbeigi,Nasrin Farhadian 대한치과교정학회 2015 대한치과교정학회지 Vol.45 No.5

Objective: The aim of this study was to investigate three-dimensional molar displacement after distalization via miniscrews and a horizontal modification of the trans-palatal-arch (TPA). Methods: The subjects in this clinical trial were 26 Class II patients. After the preparation of a complete set of diagnostic records, miniscrews were inserted between the maxillary 2nd premolar and 1st molar on the palatal side. Elastic modules connected to the TPA exerting an average force of 150?200 g/side parallel to the occlusal plane were applied. Cone-beam computed tomography was utilized to evaluate the position of the miniscrews relative to the adjacent teeth and maxillary sinus, and the direction of force relative to molar furcation. The distances from the central point of the incisive papilla to the mesiopalatal cusps of the 1st maxillary molars and the distances between the mesiopalatal cusps of the left and right molars were measured to evaluate displacement of the maxillary molars on the horizontal plane. Interocclusal space was used to evaluate vertical changes. Results: Mean maxillary 1st molar distalization was 2.3 ± 1.1 mm, at a rate of 0.4 ± 0.2 mm/month, and rotation was not significant. Intermolar width increased by 2.9 ± 1.8 mm. Molars were intruded relative to the neighboring teeth, from 0.1 to 0.8 mm. Conclusions: Distalization of molars was possible without extrusion, using the appliance investigated. The intrusive component of force reduced the rate of distal movement.

A review on pavement porous concrete using recycled waste materials

Toghroli, Ali,Shariati, Mahdi,Sajedi, Fathollah,Ibrahim, Zainah,Koting, Suhana,Mohamad, Edy Tonnizam,Khorami, Majid 국제구조공학회 2018 Smart Structures and Systems, An International Jou Vol.22 No.4

Pavements porous concrete is a noble structure design in the urban management development generally enabling water to be permeated within its structure. It has also capable in the same time to cater dynamic loading. During the technology development, the quality and quantity of waste materials have led to a waste disposal crisis. Using recycled materials (secondary) instead of virgin ones (primary) have reduced landfill pressure and extraction demanding. This study has reviewed the waste materials (Recycled crushed glass (RCG), Steel slag, Steel fiber, Tires, Plastics, Recycled asphalt) used in the pavement porous concretes and report their respective mechanical, durability and permeability functions. Waste material usage in the partial cement replacement will cause the concrete production cost to be reduced; also, the concretes' mechanical features have slightly affected to eliminate the disposal waste materials defects and to use cement in Portland cement (PC) production. While the cement has been replaced by different industrial wastes, the compressive strength, flexural strength, split tensile strength and different PC permeability mixes have depended on the waste materials' type applied in PC production.

Evaluation and comparison of GRP and FRP applications on the behavior of RCCs made of NC and HSC

Mohsen Shafieinia,Fathollah Sajedi 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.23 No.5

This paper presents the results of axial pressure testing on reinforced concrete columns (RCCs) filled with confined normal concrete (NC) and high-strength concrete (HSC) using glass-fiber reinforced plastic pipes (GRP) casing as well as fiber reinforced polymer (FRP). This study aims to evaluate the behavior and mechanical properties of columns confined with GRP casing and FRP wrapping under pressure loads. The major parameters in the experiments were the type of concrete, the effect of GRP casing and FRP wrapping, as well as the number of FRP layers. 12 cylindrical RCCs (150*600) mm were prepared and divided into two groups, NC and HSC, and each group was divided into two parts. In each part, one column was without FRP strengthening layer, a column was wrapped with one FRP layer and another column with two FRP layers. All columns were tested under concentrated compression load. The results of the study showed that the utilization of FRP wrapping and GRP casing improved compression capacity and ductility of RCCs. The addition of one and two layers-FRP wrapping increased compression capacity in the NC group to an average of 18.5% and 26.5% and to an average of 10.2% and 24.8% in the HSC group. Meanwhile, the utilization of GRP casing increased the compression capacity of the columns by 4 times in the NC group and 3.38 times in the HSC group. The results indicated that although both FRP wrapping and GRP casing result in confinement, the GRP casing resulted in increased compression capacity and ductility of the RCCs due to higher confinement. Furthermore, the confinement effect was higher on columns made with NC.

Twin models for high-resolution visual inspections

Xiao Liang,Seyedomid Sajedi,Kareem A. Eltouny 국제구조공학회 2023 Smart Structures and Systems, An International Jou Vol.31 No.4

Visual structural inspections are an inseparable part of post-earthquake damage assessments. With unmanned aerial vehicles (UAVs) establishing a new frontier in visual inspections, there are major computational challenges in processing the collected massive amounts of high-resolution visual data. We propose twin deep learning models that can provide accurate highresolution structural components and damage segmentation masks efficiently. The traditional approach to cope with high memory computational demands is to either uniformly downsample the raw images at the price of losing fine local details or cropping smaller parts of the images leading to a loss of global contextual information. Therefore, our twin models comprising Trainable Resizing for high-resolution Segmentation Network (TRS-Net) and DmgFormer approaches the global and local semantics from different perspectives. TRS-Net is a compound, high-resolution segmentation architecture equipped with learnable downsampler and upsampler modules to minimize information loss for optimal performance and efficiency. DmgFormer utilizes a transformer backbone and a convolutional decoder head with skip connections on a grid of crops aiming for high precision learning without downsizing. An augmented inference technique is used to boost performance further and reduce the possible loss of context due to grid cropping. Comprehensive experiments have been performed on the 3D physicsbased graphics models (PBGMs) synthetic environments in the QuakeCity dataset. The proposed framework is evaluated using several metrics on three segmentation tasks: component type, component damage state, and global damage (crack, rebar, spalling). The models were developed as part of the 2nd International Competition for Structural Health Monitoring.